CBSE Class 7 Maths Large Numbers Around Us (Class 7 NCERT New) Quiz 18

1. Evaluate 103 × 103. Choose the correct product.

A 10,306 B 10,603 C 10609 D 1,06,003

2. Is there a connection between the number of digits in the factors and the digits in their product? Choose the best rule.

A The product always has exactly the sum of the digits of the factors. B The product has either (m + n − 1) or (m + n) digits when multiplying an m-digit number by an n-digit number. C The product always has one more digit than the larger factor. D There is no predictable rule.

3. Roxie says that the product of two 2-digit numbers can only be a 3- or a 4-digit number. Is she correct?

A Yes, because 10 × 10 is 100 and 99 × 99 is less than 10,000 B No, because 2-digit numbers can give 2-digit products C No, because products can be 5-digit numbers D Cannot be determined

4. To check Roxie’s claim about 2-digit numbers, which method is better than trying every multiplication?

A Use the smallest product 10 × 10 and the greatest product 99 × 99 to bound the number of digits. B Multiply all pairs of 2-digit numbers and count the digits. C Pick any random pair and generalize. D Convert the numbers to fractions first.

5. Can multiplying a 3-digit number with another 3-digit number give a 4-digit number?

A Yes, sometimes B No, because the smallest 3-digit product 100 × 100 is 10,000 C Only if one number is less than 100 D Only when both numbers end in zero

6. Can multiplying a 4-digit number with a 2-digit number give a 5-digit number?

A Yes, for example 1000 × 10 = 10,000 B No, it must be 6-digit C Only if the 2-digit number is prime D Only if the 4-digit number is less than 1000

7. Calculate 1250 × 380 to uncover the number of kirtanas said to have been composed by Purandaradasa according to legends. Read the product as a number.

A 4,75,000 B 47,500 C 475,000,000 D 4750

8. Calculate 2100 × 70,000 to uncover the approximate distance, in kilometers, between the Earth and the Sun as given in the fact box. Choose the correct value.

A 147,000,000 km B 152,000,000 km C 14,700,000 km D 1,470,000,000 km

9. According to the blue fact box, the farthest distance between the Earth and the Sun during the year is about how many kilometers?

A 152 million km B 147 million km C 1.52 billion km D 105 million km

10. How did scientists first measure the distance between the Earth and the Sun? Choose the method that best explains a practical approach referenced by astronomers.

A By using a gigantic measuring tape stretched through space B By geometric calculations from observations of planetary motions and parallax C By timing how long sunlight takes to reach Earth with a stopwatch D By sending a probe with an odometer to the Sun in a single trip