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K.V. IAT GIRINAGAR, PUNE – 25. Mrs. Pushpa Prakash. Class – IV Subject – Mathematics Unit – 6 Addition Subtraction Topic – Estimating Sums and Difference. ESTIMATING SUMS. Round The Number To The Nearest 10 And Add. 1 73 70 + 49 +50 122 120
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K.V. IAT GIRINAGAR, PUNE – 25 Mrs. Pushpa Prakash Class – IV Subject – Mathematics Unit – 6 Addition Subtraction Topic – Estimating Sums and Difference
Round The Number To The Nearest10 And Add 1 73 70 + 49+50 122120 Answer : Actual - 122 Estimate - 120 1. 70 ------- 73----- 75 ------------- 80 2. 40 ----------------- 45 ------- 49 - 50
Round The Number To The Nearest 100 And Add 1. 100 -------------- 150 ----154 ------- 200 • 100 ------ 129 -- 150 ----------------- 200 1 154 200 + 129 + 100 283300 Answer : Actual – 283 Estimate - 300
Round The Number To The Nearest 1000 And Add 1. 1000 ------------ 1500 ----1705 ------ 2000 • 7000 ------------ 7500 --------7807--- 8000 • 1000 ---1395 -- 1500 ----------------- 2000 1 1 1 1 1 31703 32000 + 47807 + 48000 + 11397 + 11000 9090791000 Answer : Actual – 90907 Estimate - 91000
Exercise • Nearest 10 69 42 57 + 78 + 37 + 74 . . . (b) Nearest 100 4160 7358 + 2397 + 5763 . .
Exercise (c) Nearest 1000 26379 6942 1 + 76689 + 43587 . .
Estimate the difference to the nearest 10 And Subtract Solution- E.g. 8 12 1 9 2 1 9 0 - 1 6 8 - 1 7 0 0 2 40 2 0 Ans: Actual-24 Estimate-20
Example 2 8 12 9 2 9 0 - 3 5 - 4 0 5 75 0 Ans: Actual-57 Estimate-50
Estimate the difference to the nearest 100 And Subtract Solution- E.g. 6 12 6 13 7 2 9 8 7 3 0 0 - 2 5 6 1 - 2 6 0 0 4 7 3 74 7 0 0 Ans:Actual-4737 Estimate-4700
Estimate the difference to the nearest 1000 And Subtract Solution- E.g. 4 10 5 7 5 0 9 5 8 0 0 0 - 4 1 3 9 9 - 4 1 0 0 0 1 6 1 1 01 7 0 0 0 Ans:Actual-1610 Estimate-1700
Exercise • Nearest ten 9 1 8 5 6 - 6 8 - 1 3 9 ___ ____ (b) Nearest hundred 6 1 5 8 4 6 7 2 - 4 4 2 9 - 1 0 8 5 _____ _____