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E:\Working\Focus_Learning\Math_Genius_4_(25-10-2023)\Open_Files\Chap-02
\\December 7, 2023 3:54 PM Bharat Arora P-6 Reader _________________________ Date: ___________________74

estimated Sum Actual Sum
tth th H t O tth th H t O Thus, 90,000 is the

4 0 0 0 0 1 1 estimated sum and

+ 5 0 0 0 0 4 2 7 2 6 89,091 is the actual
9 0 0 0 0 + 4 6 3 6 5 sum.
8 9 0 9 1

example 4: Estimate the difference of 56,238 and 29,562.

Solution: Rounding off 56,238 to the nearest ten thousands 60,000

(Since thousands digit, i.e., 6 > 5)

Rounding off 29,562 to the nearest ten thousands 30,000

(Since thousands digit, i.e., 9 > 5)

estimated difference Actual difference

tth th H t O tth th H t O
6 0 0 0 0 15 11 Thus, the estimated

– 3 0 0 0 0 4 5 1 13 difference is 30,000
3 0 0 0 0 5 6 2 3 8 and the actual
– 2 9 5 6 2 difference is 26,676.
2 6 6 7 6

Practice time 2h

1. estimate the sum of the following.

(a) 2,136 + 1,258 (b) 4,736 + 7,192 (c) 7,572 + 8,780

(d) 12,733 + 45,264 (e) 74,732 + 22,486 (f) 14,524 + 34,056

(g) 27,426 + 11,548 (h) 25,964 + 12,736 (i) 65,214 + 18,307

2. estimate the difference of the following.

(a) 3,136 – 1,285 (b) 4,736 – 3,192 (c) 27,783 – 4,572

(d) 42,733 – 15,264 (e) 84,232 – 32,586 (f) 64,254 – 44,560

(g) 37,427 – 21,445 (h) 35,464 – 22,336 (i) 95,840 – 10,379

3. There are 65,234 men, 60,556 women and 78,954 children in a city. Find the

approximate population of the city. Find the difference between the actual sum
and the estimated sum.

48 Mathematics-4