3rd Grade Rounding to the Nearest 10 and 100 Worksheet Solutions (PDF)
This grade 3 rounding answers for 3rd Grade covers rounding to the nearest 10 and 100 (Common Core 3.NBT.A.1), with a free PDF to print.
Grade 3 · Common Core State Standards: 3.NBT.A.1
Grade 3 rounding answers: exercises 1 to 10
Exercise 1 – Down to the nearest ten
63 is before the halfway point 65, so it is closer to 60.
63 rounds to 60.
Exercise 2 – Up to the nearest ten
78 is past the halfway point 75, so it is closer to 80.
78 rounds to 80.
Exercise 3 – Halfway number
A halfway number rounds up.
45 rounds to 50.
Exercise 4 – Four tens
\(27\) rounds to \(30\), \(52\) rounds to \(50\), \(89\) rounds to \(90\), \(94\) rounds to \(90\).
30, 50, 90, 90
Exercise 5 – Down to the nearest hundred
The halfway point is 350. Since 372 is past 350, it is closer to 400.
372 rounds to 400.
Exercise 6 – Stay at the hundred
418 is before the halfway point 450, so it is closer to 400.
418 rounds to 400.
Exercise 7 – Halfway hundred
250 is exactly halfway between 200 and 300. The tens digit is 5, so round up.
250 rounds to 300.
Exercise 8 – Four hundreds
\(149\) rounds to \(100\), \(583\) rounds to \(600\), \(761\) rounds to \(800\), \(899\) rounds to \(900\).
100, 600, 800, 900
Exercise 9 – Tens in the hundreds
\(346\) rounds to \(350\), \(658\) rounds to \(660\), \(705\) rounds to \(710\), \(999\) rounds to \(1{,}000\).
350, 660, 710, 1,000
Exercise 10 – Round up to 100
Nearest ten: the ones digit is 6, so 96 rounds up to 100.
Nearest hundred: 96 is closer to 100 than to 0, so it rounds to 100.
100 and 100.
Exercises 11 and up
Exercise 11 – Round up to 1,000
The tens digit of 962 is 6, so it rounds up to 1,000.
The tens digit of 991 is 9, so it rounds up to 1,000.
1,000 and 1,000.
Exercise 12 – Both roundings
Nearest ten: the ones digit 4 rounds down, so \(684\) rounds to 680.
Nearest hundred: the tens digit 8 rounds up, so \(684\) rounds to 700.
Exercise 13 – Which ten is closer?
\(86 – 80 = 6\) and \(90 – 86 = 4\). The distance to 90 is smaller.
86 rounds to 90.
Exercise 14 – Numbers that round to 70
65 is halfway between 60 and 70 and rounds up. 74 is the last number before the halfway point 75.
Least 65, greatest 74.
Exercise 15 – Numbers that round to 500
450 is halfway between 400 and 500, so it rounds up to 500. 549 is the last number before 550.
Least 450, greatest 549.
Exercise 16 – Find the error
Ben looked at the ones digit. To round to the nearest hundred, look at the tens digit, which is 4. It rounds down.
349 rounds to 300.
Exercise 17 – Missing digit
The number rounds up when the tens digit is 5 or more.
5, 6, 7, 8, or 9.
Exercise 18 – Compare roundings
Nearest ten: 645 rounds to 650. Nearest hundred: the tens digit 4 rounds down to 600.
\(650 > 600\), so 650 is greater.
Exercise 19 – Soccer crowd
Nearest ten: the ones digit 8 rounds up, so 440.
Nearest hundred: the tens digit 3 rounds down, so 400.
440 fans and 400 fans.
Exercise 20 – Farm stand estimate
Estimate: \(200 + 200 = 400\). Exact: \(187 + 214 = 401\).
About 400; exactly 401.
Exercise 21 – Road trip estimate
468 rounds to 470 and 289 rounds to 290. Estimate: \(470 – 290 = 180\).
Exact: \(468 – 289 = 179\).
About 180 miles; exactly 179 miles.
Exercise 22 – Library books
Nearest hundred: \(400 + 300 = 700\). Nearest ten: \(370 + 300 = 670\).
Exact: \(372 + 295 = 667\).
The difference from 667 is 33 for the first estimate and 3 for the second. The nearest-ten estimate, 670, is closer.
Exercise 23 – Is the estimate right?
126 rounds to 100 and 158 rounds to 200, so the estimate is \(100 + 200 = 300\), not 400.
Exact: \(126 + 158 = 284\), which is close to 300.
Priya is not right; about 300 tickets.
Exercise 24 – Fair attendance
650 is halfway between 600 and 700 and rounds up. 749 rounds down from 750.
Least 650, greatest 749.
Key facts behind this grade 3 rounding answers
- Rounding to the nearest 10 depends on the ones digit.
- Rounding to the nearest 100 depends on the tens digit.
- A digit of 5 or more rounds up. A digit of 4 or less rounds down.
- A number exactly halfway rounds up, so 45 rounds to 50.
- Rounded numbers make quick estimates for sums and differences.
How to use this grade 3 rounding answers
Cover each solution, solve the exercise again, then uncover it and compare every line. If your answer differs, find the first step that changed and redo the exercise from there.
Download the grade 3 rounding answers as a PDF with the button below and keep it with your notes.
Download the grade 3 rounding answers as a PDF with the button below and keep it with your notes.
All Grade 3 chapters: Grade 3 math.
