Page 48 - Math Genius C5

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\\October 8, 2025 12:09 PM Bharat Arora P-9 Reader _________________________ Date: ___________________74

( c) School children in Delhi collected `98,762 for flood-affected people. This is to be ( c) rounded to
distributed among 437 people equally. How much does each person get? 4465 nearest 1000 4000 estimated product Actual product

( d) A wholesale supplier sold 3,49,300 kg of mangoes in boxes last year. How many rounded to × 4 0 0 0 × 4 4 6 5
8
1 0
boxes did he use throughout the year if there were 35 kg of mangoes in each box? 8 nearest 10 10 4 0 0 0 0 3 5 7 2 0
EStiMation in oPErationS The estimated product is close to the actual product.

We have learnt in the previous chapter how to round off a number to a certain place. ( d) estimated quotient Actual quotient
To round off a number, we look at the digit to the right of the place to which you are 24,581 20,000 (Rounding off to the nearest ten thousand) 5 7 1
2 4 5 8 1
rounding. 43 40 (Rounding off to the nearest ten) 43 2 1 5
If the digit is 5 or greater, round up. 20,000 ÷ 40 = 500 3 0 8
If the digit is less than 5, round down. 3 0 1
7 1
Math Insight The estimated quotient is close to the actual quotient. 4 3
A number can be rounded off to any place according to the situation. However, the estimated 28
answer should be close to the actual answer.

examples: Rounding off 568 to the nearest hundred 600 Think Tank Logical Thinking

Rounding off 8177 to the nearest thousand 8000 Ask your parents’ monthly income and estimate their yearly income. What is the
difference between their actual and estimated yearly incomes?
Rounding off 28,139 to the nearest ten thousand 30,000
Rounding off 1,50,000 to the nearest lakh 2,00,000
Sometimes in real-life situations, we need a quick answer. In such situations estimation helps. Practice time 2E

Sometimes, the actual addition, subtraction, multiplication or division of the numbers takes 1. estimate the value of:
more time to calculate. In these cases, we find the estimated sum, difference, product, or ( a) 31,972 + 10,322 (b) 2575 × 124 (c) 7,21,994 – 66,159 (d) 2,56,311 ÷ 578
quotient by rounding off the numbers to the nearest tens, hundreds, thousands and so on. 2. the table given below shows how much Varun spent on some items.

example 1: Estimate the answer of each of the following.
( a) 2960 + 1730 (b) 9300 – 6420 (c) 4465 × 8 (d) 24,581 ÷ 43 Item Amount in (`)
New car 6,29,575
Solution: Washing machine 28,675

(a) rounded to estimated sum Actual sum
2960 nearest 1000 3000 3 0 0 0 2 9 6 0 Mobile phone 36,435

rounded to + 2 0 0 0 + 1 7 3 0 Earphones 3970
1730 nearest 1000 2000 5 0 0 0 4 6 9 0 Round off each amount to the nearest thousand and estimate:

The estimated sum is close to the actual sum. ( a) total amount spent on the washing machine and mobile phone.

( b) rounded to estimated difference Actual difference ( b) the difference of the costs of the washing machine and the earphones.
9300 nearest 1000 9000 9 0 0 0 8 12 10

rounded to – 6 0 0 0 9 3 0 0 ( c) total amount spent by Varun.
6420 nearest 1000 6000 3 0 0 0 – 6 4 2 0 3. Find the estimated quotient of 3,25,870 and 5543.
2 8 8 0
4. Find the actual sum and the estimated sum of 4,83,479 and 5,67,891 by rounding off
The estimated difference is close to the actual difference. to the nearest 10,000.

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