Estimating, subtracting and liquid volume
Answers are for parents and teachers.
1
Round to the nearest hundred: 249, 250, 851 and 1,049.
249 rounds to 200, 250 rounds to 300, 851 rounds to 900 and 1,049 rounds to 1,000.
2
Estimate 596 + 307 by rounding. Then find the exact sum.
596 is about 600 and 307 is about 300, so the estimate is 900. The exact sum is 903.
3
Find 804 − 367 and check your answer by adding.
804 − 367 = 437. Check: 437 + 367 = 804.
4
A library had 7,400 books. It lent 2,150 books. How many books are left on the shelves?
7,400 − 2,150 = 5,250 books. Check: 5,250 + 2,150 = 7,400.
5
How many millilitres are in 5 L? How many glasses of 250 mL can be filled from 2 L of juice?
5 L = 5,000 mL. 2 L = 2,000 mL, and 4 glasses fill 1 L, so 2 L fills 2 × 4 = 8 glasses.