Page 140 - New Medley 4 Semester 1
P. 140
Many a times we don’t need the exact difference but just a round about
idea of what the difference would be. This is called finding an estimate.
We round the numbers to nearest tens, hundreds, thousands or ten
thousands depending upon the accuracy we want. We now subtract these
rounded figures to get an estimate.
Example 15: Estimate 65106 – 27678 by rounding to nearest tens.
Solution: Rounding off to tens
65106 rounds to 6 5 1 1 0
27678 rounds to – 2 7 6 8 0
Estimated difference 3 7 4 3 0
Example 16: Estimate 445925 – 417879 by rounding to nearest hundreds.
Solution: Rounding off to hundreds
445925 rounds to 4 4 5 9 0 0
417879 rounds to – 4 1 7 9 0 0
Estimated difference 2 8 0 0 0
Example 17: Estimate 55719 – 37216 by rounding to nearest thousands.
Solution: Rounding off to thousands
55719 rounds to 5 6 0 0 0
37216 rounds to – 3 7 0 0 0
Estimated difference 1 9 0 0 0
Example 18: Estimate 567725 – 277278 by rounding to nearest ten
thousands.
Solution: Rounding off to ten thousands
567725 rounds to 5 7 0 0 0 0
277278 rounds to – 2 8 0 0 0 0
Estimated difference 2 9 0 0 0 0
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