Rounding to Nearest 10 and 100 — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 73 rounded to the nearest ten is 70.
73 rounded to the nearest ten is 70 because the ones digit (3) is less than 5, so we round down.
2. 581 rounded to the nearest hundred is 600.
581 rounded to the nearest hundred is 600 because the tens digit (8) is 5 or greater, so we round up.
3. 46 rounded to the nearest ten is 50.
46 rounded to the nearest ten is 50 because the ones digit (6) is 5 or greater, so we round up.
4. 825 rounded to the nearest hundred is 800.
825 rounded to the nearest hundred is 800 because the tens digit (2) is less than 5, so we round down.
5. 19 + 42 is about 60 when you round each number to the nearest ten.
19 rounds to 20 and 42 rounds to 40, so 20 + 40 = 60.
6. 394 rounded to the nearest hundred is 400.
394 rounded to the nearest hundred is 400 because the tens digit (9) is 5 or greater, so we round up.
7. 155 rounded to the nearest ten is 160.
155 rounded to the nearest ten is 160 because the ones digit (5) is 5 or greater, so we round up.
8. 67 - 23 is about 50 when you round each number to the nearest ten.
67 rounds to 70 and 23 rounds to 20, so 70 - 20 = 50.
9. 648 rounded to the nearest hundred is 600.
648 rounded to the nearest hundred is 600 because the tens digit (4) is less than 5, so we round down.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
38
→ 40
200
762
→ 800
500
150
→ 200
40
489
→ 500
800
38 rounds to 40 (nearest ten), 762 rounds to 800 (nearest hundred), 150 rounds to 200 (nearest hundred), and 489 rounds to 500 (nearest hundred).