{"id":31496,"date":"2026-05-11T16:49:42","date_gmt":"2026-05-11T11:19:42","guid":{"rendered":"https:\/\/mycbseguide.com\/blog\/?p=31496"},"modified":"2026-05-11T16:51:50","modified_gmt":"2026-05-11T11:21:50","slug":"the-world-of-numbers-ncert-solutions-class-9-ganita-manjari","status":"publish","type":"post","link":"https:\/\/mycbseguide.com\/blog\/the-world-of-numbers-ncert-solutions-class-9-ganita-manjari\/","title":{"rendered":"The World of Numbers – NCERT Solutions Class 9 Ganita Manjari"},"content":{"rendered":"\n

The World of Numbers – NCERT Solutions Class 9 Maths Ganita Manjari includes all the questions with solutions given in NCERT Class 9 Ganita Manjari<\/a> textbook.<\/p>\n\n\n\n

NCERT Solutions Class 9<\/h2>\n\n\nEnglish Kaveri<\/a>\n\n\nHindi Ganga<\/a>\n\n\nSanskrit Sharada<\/a>\n\n\nMaths Ganita Manjari<\/a>\n\n\nScience Exploration<\/a>\n\n\nSocial Understanding Society<\/a>\n\n\n\n

The World of Numbers \u2013 NCERT Solutions<\/h2>\n\n\n\n
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Q.1:<\/p>\n\n\n\n

A merchant in the port city of Lothal is exchanging bags of spices for copper ingots. He receives 15 ingots for every 2 bags of spices. If he brings 12 bags of spices to the market, how many copper ingots will he leave with?<\/p>\n\n\n\n

Solution:<\/p>\n\n\n\n

Given that:
2 bags of spices {tex}=15{\/tex} ingots
So, 1 bag of spices {tex}=15 \/ 2{\/tex} ingots
Similarly, for 12 bags of spices<\/p>\n\n\n\n

{tex}=12 \\times(15 \/ 2){\/tex}
{tex}=6 \\times 15{\/tex}
{tex}=90{\/tex}<\/p>\n\n\n\n

Therefore, the merchant will leave with 90 copper ingots.<\/p>\n\n\n\n

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Q.2:<\/p>\n\n\n\n

Look at the sequence of numbers on one column of the Ishango bone: {tex}11,13,17,19{\/tex}. What do these numbers have in common? List the next three numbers that fit this pattern.<\/p>\n\n\n\n

Solution:<\/p>\n\n\n\n

The numbers {tex}11,13,17,19{\/tex} are all prime numbers (numbers that have only two factors: 1 and itself).
Next three prime numbers after 19 are {tex}23,29,31{\/tex}.
Therefore, the next three numbers are {tex}23,29,31{\/tex}.<\/p>\n\n\n\n

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Q.3:<\/p>\n\n\n\n

We know that Natural Numbers are closed under addition (the sum of any two natural numbers is always a natural number). Are they closed under subtraction? Provide a couple of examples to justify your answer.<\/p>\n\n\n\n

Solution:<\/p>\n\n\n\n

Closure means the result should also be a natural number.
Examples:<\/p>\n\n\n\n

    \n
  1. {tex}5-3=2{\/tex} (Natural number)<\/li>\n\n\n\n
  2. {tex}3-5=-2{\/tex} (Not a natural number)<\/li>\n<\/ol>\n\n\n\n

    Since subtraction can give a negative number, so natural numbers are not closed under subtraction.<\/p>\n\n\n\n

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    Q.4:<\/p>\n\n\n\n

    Ancient Indians used the joints of their fingers to count, a practice still seen today. Each finger has 3 joints, and the thumb is used to count them. How many can you count on one hand? How does this relate to the ancient base-12 counting systems?<\/p>\n\n\n\n

    Solution:<\/p>\n\n\n\n

    Each finger (except thumb) has 3 joints.
    Number of fingers used {tex}=4{\/tex} (excluding thumb)
    Total joints {tex}=4 \\times 3=12{\/tex}
    So, we can count up to 12 using one hand.
    Relation to base-12 system:<\/strong>
    Since counting reaches 12 on one hand, it naturally leads to a base-12 (duodecimal) counting system used in ancient times.
    Therefore:<\/p>\n\n\n\n