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Rounding Worksheets

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Round to the nearest 10 and 100 on number lines and with the place value rule, round the same number both ways, and estimate sums and differences.

Download the rounding worksheets worksheets

Round to the nearest 10

Round on number lines, then 2- and 3-digit numbers with the ones digit rule.

Round to the nearest 100

Round on number lines, then 3-digit numbers with the tens digit rule.

Round to the nearest 10 and 100

Round each number two ways in a table.

Estimate sums and differences

Round to estimate, then find the exact answer and compare.

Print at 100% (actual size) for the cleanest tracing lines.

About these rounding worksheets worksheets

Rounding means finding the nearest ten or hundred. 47 is between 40 and 50, and it is closer to 50, so 47 rounds to 50. 347 is between 300 and 400, closer to 300, so it rounds to 300 to the nearest hundred. Halfway numbers like 45 and 350 round up.

The number line pages show why: the number sits on a line between two tens (or hundreds) with the halfway point marked, and children decide which end is closer. Then the place value pages practice the quick rule: look at the digit to the right. 0 to 4, round down; 5 to 9, round up.

The estimation pages put rounding to work: estimate a sum or difference, then find the exact answer and see if it is close. Every page has an answer key on page 2 and prints in black and white on US Letter or A4.

Standards

  • CCSS.MATH.CONTENT.3.NBT.A.1Use place value understanding to round whole numbers to the nearest 10 or 100.
  • CCSS.MATH.CONTENT.3.OA.D.8Solve two-step word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

How to use them

  1. Start with the number line pages for the nearest 10, then the nearest 100.
  2. Move to Round to the Nearest 10 and Round to the Nearest 100 once children can explain why.
  3. Use Round to the Nearest 10 and 100 to show the same number rounding to different answers.
  4. Use Estimate, Then Solve whenever children add and subtract 3-digit numbers, to catch big mistakes.

Teaching tips

  • Find the two tens (or hundreds) the number is between first. The answer is always one of them.
  • To the nearest 10, look at the ones. To the nearest 100, look at the tens.
  • Halfway always rounds up: 65 rounds to 70, and 250 rounds to 300.
  • Numbers near the top of a hundred can round up to the next one: 961 rounds to 1000.

Questions teachers and parents ask

How do you round to the nearest 10?

Look at the ones digit. If it is 0 to 4, keep the tens digit and make the ones 0 (73 rounds to 70). If it is 5 to 9, add one ten (75 and 78 round to 80).

How do you round to the nearest 100?

Look at the tens digit. If it is 0 to 4, round down (432 rounds to 400). If it is 5 to 9, round up (452 rounds to 500).

Why do numbers ending in 5 round up?

A number like 45 is exactly halfway between 40 and 50. Mathematicians agree to round halfway numbers up so everyone gets the same answer.

Are there answer keys?

Yes. Every page has an answer key on page 2. The number line keys show which end the number is closer to.