{"id":2270,"date":"2026-05-26T22:39:57","date_gmt":"2026-05-26T17:09:57","guid":{"rendered":"https:\/\/mymockmate.com\/notes\/?p=2270"},"modified":"2026-06-18T12:05:48","modified_gmt":"2026-06-18T06:35:48","slug":"ncert-class-9-maths-exercise-3-2-solutions-world-of-numbers","status":"publish","type":"post","link":"https:\/\/mymockmate.com\/notes\/ncert-class-9-maths-exercise-3-2-solutions-world-of-numbers\/","title":{"rendered":"NCERT Class 9 Maths Exercise 3.2 Solutions | World of Numbers"},"content":{"rendered":"<div class=\"mymoc-top mymoc-entity-placement\" id=\"mymoc-2255792008\"><div id=\"mymoc-2745253571\"><a href=\"https:\/\/amzn.to\/4xnw9oY\" aria-label=\"head-phones\"><img src=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/head-phones.png\" alt=\"\" srcset=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/head-phones.png 1301w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/head-phones-300x80.png 300w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/head-phones-1024x274.png 1024w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/head-phones-768x205.png 768w\" sizes=\"(max-width: 1301px) 100vw, 1301px\" width=\"1301\" height=\"348\"><\/a><\/div><\/div><div class=\"pdfprnt-buttons pdfprnt-buttons-post pdfprnt-top-bottom-right\"><a href=\"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/posts\/2270?print=print\" class=\"pdfprnt-button pdfprnt-button-print\" target=\"_blank\"><img decoding=\"async\" src=\"https:\/\/mymockmate.com\/notes\/wp-content\/plugins\/pdf-print\/images\/print.png\" alt=\"image_print\" title=\"Print Content\"><span class=\"pdfprnt-button-title pdfprnt-button-print-title\">Print<\/span><\/a> <span class=\"pdfprnt-count-generation\">20<\/span><\/div>\n<h1 class=\"wp-block-heading\">Short Intro<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Exercise 3.2 of <strong>&ldquo;The World of Numbers&rdquo;<\/strong> focuses on integers, negative numbers, and Brahmagupta&rsquo;s arithmetic laws. Students learn how to solve real-life problems involving temperature changes, debts, profits, and operations with negative numbers. These step-by-step solutions are written in simple English for easy understanding and exam preparation.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Quick Information Box<\/h1>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Topic<\/th><th>Details<\/th><\/tr><\/thead><tbody><tr><td>Chapter<\/td><td>The World of Numbers<\/td><\/tr><tr><td>Exercise<\/td><td>3.2<\/td><\/tr><tr><td>Subject<\/td><td>Mathematics<\/td><\/tr><tr><td>Class<\/td><td>Grade 9<\/td><\/tr><tr><td>Main Concept<\/td><td>Integers &amp; Brahmagupta&rsquo;s Laws<\/td><\/tr><tr><td>Difficulty Level<\/td><td>Easy<\/td><\/tr><tr><td>Useful For<\/td><td>School Exams &amp; Practice<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">Concepts Used (Topics Covered)<\/h1>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Positive and Negative Numbers<\/li>\n\n\n\n<li>Integers<\/li>\n\n\n\n<li>Brahmagupta&rsquo;s Laws<\/li>\n\n\n\n<li>Multiplication of Integers<\/li>\n\n\n\n<li>Division of Integers<\/li>\n\n\n\n<li>Real-life Applications of Integers<\/li>\n\n\n\n<li>Temperature Problems<\/li>\n\n\n\n<li>Profit and Loss Using Integers<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\">Important Formulas<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Integer Set<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><mi mathvariant=\"double-struck\">Z<\/mi><mo>=<\/mo><mo stretchy=\"false\">{<\/mo><mo>&hellip;<\/mo><mo separator=\"true\">,<\/mo><mo>&minus;<\/mo><mn>3<\/mn><mo separator=\"true\">,<\/mo><mo>&minus;<\/mo><mn>2<\/mn><mo separator=\"true\">,<\/mo><mo>&minus;<\/mo><mn>1<\/mn><mo separator=\"true\">,<\/mo><mn>0<\/mn><mo separator=\"true\">,<\/mo><mn>1<\/mn><mo separator=\"true\">,<\/mo><mn>2<\/mn><mo separator=\"true\">,<\/mo><mn>3<\/mn><mo separator=\"true\">,<\/mo><mo>&hellip;<\/mo><mtext>&thinsp;<\/mtext><mo stretchy=\"false\">}<\/mo><\/mrow><annotation encoding=\"application\/x-tex\">\\mathbb{Z}=\\{\\dots,-3,-2,-1,0,1,2,3,\\dots\\}<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Product Rules of Integers<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mi>a<\/mi><mo stretchy=\"false\">)<\/mo><mo>&times;<\/mo><mo stretchy=\"false\">(<\/mo><mo>+<\/mo><mi>b<\/mi><mo stretchy=\"false\">)<\/mo><mo>=<\/mo><mo>&minus;<\/mo><mi>a<\/mi><mi>b<\/mi><\/mrow><annotation encoding=\"application\/x-tex\">(-a)\\times(+b)=-ab<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mi>a<\/mi><mo stretchy=\"false\">)<\/mo><mo>&times;<\/mo><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mi>b<\/mi><mo stretchy=\"false\">)<\/mo><mo>=<\/mo><mo>+<\/mo><mi>a<\/mi><mi>b<\/mi><\/mrow><annotation encoding=\"application\/x-tex\">(-a)\\times(-b)=+ab<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Zero Property<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><mi>a<\/mi><mo>+<\/mo><mn>0<\/mn><mo>=<\/mo><mi>a<\/mi><mo separator=\"true\">,<\/mo><mtext>&nbsp;<\/mtext><mi>a<\/mi><mo>&minus;<\/mo><mn>0<\/mn><mo>=<\/mo><mi>a<\/mi><mo separator=\"true\">,<\/mo><mtext>&nbsp;<\/mtext><mi>a<\/mi><mo>&times;<\/mo><mn>0<\/mn><mo>=<\/mo><mn>0<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">a+0=a,\\ a-0=a,\\ a\\times0=0<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Questions &amp; Step-by-Step Solutions<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Question 1<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The temperature in the high-altitude desert of Ladakh is recorded as 4 &deg;C at noon. By midnight, it drops by 15 &deg;C. What is the midnight temperature?<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Solution<\/h3>\n\n\n\n<div class=\"internal-linking-related-contents\"><a href=\"https:\/\/mymockmate.com\/notes\/class-9-maths-exercise-1-1-solutions-coordinate-geometry-ncert-solutions\/\" class=\"template-2\"><span class=\"cta\">Related Topic to Read more<\/span><span class=\"postTitle\">NCERT Class 9 Maths Exercise 1.1 Solutions | Coordinate Geometry NCERT Solutions<\/span><\/a><\/div><p class=\"wp-block-paragraph\">Initial temperature = 4&deg;C<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Temperature drop = 15&deg;C<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So,<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mn>4<\/mn><mo>&minus;<\/mo><mn>15<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">4 &ndash; 15<\/annotation><\/semantics><\/math><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mo>=<\/mo><mo>&minus;<\/mo><mn>11<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">= -11<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Answer<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The midnight temperature is:<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><menclose notation=\"box\"><mstyle scriptlevel=\"0\" displaystyle=\"false\"><mstyle scriptlevel=\"0\" displaystyle=\"false\"><mstyle scriptlevel=\"0\" displaystyle=\"true\"><mrow><mo>&minus;<\/mo><msup><mn>11<\/mn><mo>&#8728;<\/mo><\/msup><mi>C<\/mi><\/mrow><\/mstyle><\/mstyle><\/mstyle><\/menclose><\/mrow><annotation encoding=\"application\/x-tex\">\\boxed{-11^\\circ C}<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\">\n\n\n\n<h2 class=\"wp-block-heading\">Question 2<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A spice trader takes a loan (debt) of Rs. <code>850. The next day, he makes a profit (fortune) of Rs. <\/code>1,200. The following week, he incurs a loss of Rs. 450. Write this sequence as an equation using integers and calculate his final financial standing.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Solution<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Loan = &minus;850<\/p>\n\n\n\n<div class=\"internal-linking-related-contents\"><a href=\"https:\/\/mymockmate.com\/notes\/class-9-maths-exercise-1-2-solutions-coordinate-geometry-ncert-solutions\/\" class=\"template-2\"><span class=\"cta\">Related Topic to Read more<\/span><span class=\"postTitle\">NCERT Class 9 Maths Exercise 1.2 Solutions | Coordinate Geometry NCERT Solutions<\/span><\/a><\/div><p class=\"wp-block-paragraph\">Profit = +1200<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Loss = &minus;450<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Equation:<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mo>&minus;<\/mo><mn>850<\/mn><mo>+<\/mo><mn>1200<\/mn><mo>&minus;<\/mo><mn>450<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">-850 + 1200 &ndash; 450<\/annotation><\/semantics><\/math><\/p><div class=\"mymoc-middle mymoc-entity-placement\" id=\"mymoc-331100166\"><div id=\"mymoc-596905047\"><a href=\"https:\/\/amzn.to\/4fDWGbw\" aria-label=\"smartwatch\"><img src=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch.png\" alt=\"\" srcset=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch.png 1717w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-300x71.png 300w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-1024x243.png 1024w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-768x182.png 768w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-1536x364.png 1536w\" sizes=\"(max-width: 1717px) 100vw, 1717px\" width=\"1717\" height=\"407\"><\/a><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Step 1:<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mo>&minus;<\/mo><mn>850<\/mn><mo>+<\/mo><mn>1200<\/mn><mo>=<\/mo><mn>350<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">-850 + 1200 = 350<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Step 2:<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mn>350<\/mn><mo>&minus;<\/mo><mn>450<\/mn><mo>=<\/mo><mo>&minus;<\/mo><mn>100<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">350 &ndash; 450 = -100<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Answer<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Final financial standing:<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><menclose notation=\"box\"><mstyle scriptlevel=\"0\" displaystyle=\"false\"><mstyle scriptlevel=\"0\" displaystyle=\"false\"><mstyle scriptlevel=\"0\" displaystyle=\"true\"><mrow><mo>&minus;<\/mo><mtext>&#8377;<\/mtext><mn>100<\/mn><\/mrow><\/mstyle><\/mstyle><\/mstyle><\/menclose><\/mrow><annotation encoding=\"application\/x-tex\">\\boxed{-&#8377;100}<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<div class=\"internal-linking-related-contents\"><a href=\"https:\/\/mymockmate.com\/notes\/class-9-maths-end-of-chapter-exercise-solutions-coordinate-geometry-ncert-solutions\/\" class=\"template-2\"><span class=\"cta\">Related Topic to Read more<\/span><span class=\"postTitle\">NCERT Class 9 Maths End of Chapter Exercise Solutions | Coordinate Geometry<\/span><\/a><\/div><p class=\"wp-block-paragraph\">This means the trader still has a debt\/Loss of &#8377;100.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\">\n\n\n\n<h2 class=\"wp-block-heading\">Question 3<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Calculate the following using Brahmagupta&rsquo;s laws:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"819\" src=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-106-1024x819.png\" alt=\"image\" class=\"wp-image-3204\" srcset=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-106-1024x819.png 1024w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-106-300x240.png 300w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-106-768x615.png 768w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-106.png 1402w\" sizes=\"(max-width: 1024px) 100vw, 1024px\"><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Question 4<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Explain using a real-life example why subtracting a negative number is the same as adding a positive number.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Solution<\/h3>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-107-1024x683.png\" alt=\"image\" class=\"wp-image-3206\" srcset=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-107-1024x683.png 1024w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-107-300x200.png 300w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-107-768x512.png 768w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/image-107.png 1536w\" sizes=\"(max-width: 1024px) 100vw, 1024px\"><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">Common Mistakes<\/h1>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Forgetting sign rules while multiplying integers<\/li>\n\n\n\n<li>Confusing subtraction of negative numbers<\/li>\n\n\n\n<li>Writing positive answers for negative operations<\/li>\n\n\n\n<li>Ignoring real-life meaning of debts and fortunes<\/li>\n\n\n\n<li>Division sign mistakes with integers<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\">Exam Tips<\/h1>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Remember:\n<ul class=\"wp-block-list\">\n<li>Positive &times; Positive = Positive<\/li>\n\n\n\n<li>Negative &times; Negative = Positive<\/li>\n\n\n\n<li>Positive &times; Negative = Negative<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Practice temperature and money-based questions<\/li>\n\n\n\n<li>Always write signs carefully<\/li>\n\n\n\n<li>Learn Brahmagupta&rsquo;s laws properly<\/li>\n\n\n\n<li>Use step-by-step calculation in exams<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\">Practice MCQs<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">1. What is the value of:<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mn>6<\/mn><mo stretchy=\"false\">)<\/mo><mo>&times;<\/mo><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mn>4<\/mn><mo stretchy=\"false\">)<\/mo><\/mrow><annotation encoding=\"application\/x-tex\">(-6)\\times(-4)<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A) &minus;24<br>B) 24<br>C) &minus;10<br>D) 10<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Answer<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B) 24<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\">\n\n\n\n<h2 class=\"wp-block-heading\">2. What is:<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mn>0<\/mn><mo>&minus;<\/mo><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mn>9<\/mn><mo stretchy=\"false\">)<\/mo><\/mrow><annotation encoding=\"application\/x-tex\">0-(-9)<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A) &minus;9<br>B) 0<br>C) 9<br>D) &minus;18<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Answer<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C) 9<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\">\n\n\n\n<h2 class=\"wp-block-heading\">3. Which of the following is an integer?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A) <math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><mfrac><mn>1<\/mn><mn>2<\/mn><\/mfrac><\/mrow><annotation encoding=\"application\/x-tex\">\\frac12<\/annotation><\/semantics><\/math>21&#8203;<br>B) <math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><msqrt><mn>2<\/mn><\/msqrt><\/mrow><annotation encoding=\"application\/x-tex\">\\sqrt2<\/annotation><\/semantics><\/math>2&#8203;<br>C) &minus;7<br>D) 3.5<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Answer<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C) &minus;7<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\">\n\n\n\n<h2 class=\"wp-block-heading\">4. The result of:<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" display=\"block\"><semantics><mrow><mo stretchy=\"false\">(<\/mo><mo>&minus;<\/mo><mn>15<\/mn><mo stretchy=\"false\">)<\/mo><mo>&divide;<\/mo><mn>3<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">(-15)\\div3<\/annotation><\/semantics><\/math><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">is:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A) 5<br>B) &minus;5<br>C) 45<br>D) &minus;45<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Answer<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B) &minus;5<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">FAQ Section<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Q1. What are integers?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Integers are positive numbers, negative numbers, and zero.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Q2. Who introduced negative numbers formally?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Brahmagupta formally introduced negative numbers.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Q3. Why does negative &times; negative become positive?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Because removing a debt improves financial value.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Q4. Is zero a positive number?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No, zero is neither positive nor negative.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Q5. Can integers be represented on a number line?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Yes, integers are represented on a number line.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Master integers and number systems with detailed NCERT solutions, mock tests, and chapter-wise practice questions. Keep practicing daily to improve your Mathematics score and build strong concepts for higher classes.<\/p>\n<div class=\"pdfprnt-buttons pdfprnt-buttons-post pdfprnt-top-bottom-right\"><a href=\"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/posts\/2270?print=print\" class=\"pdfprnt-button pdfprnt-button-print\" target=\"_blank\"><img decoding=\"async\" src=\"https:\/\/mymockmate.com\/notes\/wp-content\/plugins\/pdf-print\/images\/print.png\" alt=\"image_print\" title=\"Print Content\"><span class=\"pdfprnt-button-title pdfprnt-button-print-title\">Print<\/span><\/a> <span class=\"pdfprnt-count-generation\">20<\/span><\/div><div class=\"mymoc-bottom mymoc-entity-placement\" id=\"mymoc-1019263093\"><div id=\"mymoc-596905047\"><a href=\"https:\/\/amzn.to\/4fDWGbw\" aria-label=\"smartwatch\"><img src=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch.png\" alt=\"\" srcset=\"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch.png 1717w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-300x71.png 300w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-1024x243.png 1024w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-768x182.png 768w, https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/06\/smartwatch-1536x364.png 1536w\" sizes=\"(max-width: 1717px) 100vw, 1717px\" width=\"1717\" height=\"407\"><\/a><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p> 20 Short Intro Exercise 3.2 of &ldquo;The World of Numbers&rdquo; focuses on integers, negative numbers, and Brahmagupta&rsquo;s arithmetic laws. Students learn how to solve&#8230;<\/p>\n","protected":false},"author":1,"featured_media":2271,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"postBodyCss":"","postBodyMargin":[],"postBodyPadding":[],"postBodyBackground":{"backgroundType":"classic","gradient":""},"footnotes":""},"categories":[4,11],"tags":[954,955,959,957,953,951,960,958,961,952,956],"class_list":["post-2270","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-class-9","category-maths-class-9","tag-brahmagupta-laws-questions-answers","tag-class-9-maths-chapter-3-solutions","tag-grade-9-maths-solutions","tag-integer-operations-class-9","tag-integers-class-9-solutions","tag-ncert-class-9-maths-exercise-3-2-solutions","tag-ncert-maths-chapter-3-answers","tag-negative-numbers-questions","tag-real-life-integer-problems","tag-world-of-numbers-exercise-3-2","tag-world-of-numbers-solutions"],"featured_image_src":"https:\/\/mymockmate.com\/notes\/wp-content\/uploads\/2026\/05\/NCERT-Class-9-Maths-Exercise-3.2-Solutions-World-of-Numbers.png","author_info":{"display_name":"Team Mymockmate","author_link":"https:\/\/mymockmate.com\/notes\/author\/bsm_adm\/"},"_links":{"self":[{"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/posts\/2270","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/comments?post=2270"}],"version-history":[{"count":3,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/posts\/2270\/revisions"}],"predecessor-version":[{"id":3208,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/posts\/2270\/revisions\/3208"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/media\/2271"}],"wp:attachment":[{"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/media?parent=2270"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/categories?post=2270"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mymockmate.com\/notes\/wp-json\/wp\/v2\/tags?post=2270"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}