Question

Calculate a rough estimate (by rounding off to nearest hundreds) and also a closer estimate (by rounding off to nearest tens):
8326 – 491. What is the difference between the two estimates?

• A. 40
• B. 50
• C. 60
• D. 70

Answer 1

The correct option is A 40

By rounding off to nearest hundreds , the rough estimate of their difference can be calculated as:

8326 can be rounded off to 8300.
491 can be rounded off to 500.
Hence, the estimated difference = 8300 - 500 = 7800 .

By rounding off to nearest tens, the rough estimate of their difference can be calculated as:

8326 can be rounded off to 8330.
491 can be rounded off to 490.
Hence, the estimated difference = 8330 - 490 = 7840.

The difference of two estimates = 7840 - 7800 = 40.
Therefore, option 'a' is correct.