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Rounding to the Nearest Ten or Hundred

A 45-minute Grade 3 lesson that teaches rounding as finding the nearer of two landmarks on a number line, rather than as a rule about the digit after the one you want.

Rounding to the Nearest Ten or Hundred is a free 45-minute Grade 3 maths lesson plan for Common Core standard 3.NBT.A.1 — round numbers to the nearest ten or hundred. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.

Grade:
Grade 3
Length:
45 minutes
Standard:
3.NBT.A.1

Grade 3 · Number & Operations in Base Ten

3.NBT.A.1

Use place value understanding to round whole numbers to the nearest 10 or 100.

Objective

Students will be able to round a whole number to the nearest ten or hundred by identifying the two nearest multiples.

Students are successful when they can

  • Names the two multiples a number sits between.
  • Decides which is nearer and rounds to it.
  • Rounds a number ending in 5 by the agreed convention and knows it is a convention.

What you need

  • Number lines marked in tens and in hundreds
  • Number cards
  • Whiteboards
  • The printable practice sheet linked at the end of this plan

The lesson

Warm-up — between which two?

5 min
  1. Give a number and ask which two tens it sits between. Then which two hundreds.
  2. Do eight. Naming the neighbours is the whole skill; deciding which is nearer is easy afterwards.

Teach — nearer, on a line

14 min
  1. Draw a number line from 40 to 50 and mark 43. Ask which end is nearer. Forty.
  2. Mark 47. Fifty is nearer. Mark 45 and let the class argue — it is exactly between.
  3. State the convention: exactly halfway rounds up. It is a rule people agreed on, not a fact about the number.
  4. Now round 347 to the nearest hundred. Draw a line from 300 to 400 and mark it. It is nearer 300.
  5. Round the same 347 to the nearest ten: between 340 and 350, nearer 350.
  6. Point out the same number rounds differently depending on what you round to, so the question always says which.
“Rounding is not about a digit. It is about which landmark you are closer to. Draw the line and the answer is obvious.”

Guided practice — mark it, then round it

12 min
  1. Pairs draw a number line, mark the number, and round it.
  2. Every card is rounded twice — to the nearest ten and to the nearest hundred — and the two answers compared.
  3. Include numbers like 96 where rounding to the nearest ten crosses a hundred.

Independent practice

11 min
  1. Students complete a rounding page.
  2. Rounding 347 to 350 when the hundred was asked for is a target error, not a rounding error, and needs the question read again.

Close

3 min
  1. Round 96 to the nearest ten and ask what happened to the hundreds digit.
  2. One hundred is a fine answer to a nearest-ten question, and that surprises people.

What goes wrong, and why

Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.

Rounds 347 to 300 when asked for the nearest ten.

Why: The rounding rule has been applied to the wrong place because the target was not identified first. Everything after that is consistent.

Fix: Name the two landmarks before doing anything else. Writing '340 and 350' on the page makes the target explicit and impossible to drift from.

Rounds 96 to the nearest ten as 90 because rounding up 'would change the hundreds'.

Why: The pupil has learned that only the target digit should change, and rounding up here changes two digits, which looks like an error.

Fix: Put it on the line. One hundred is genuinely the nearer ten, and the hundreds digit changing is a consequence rather than a problem.

Applies a memorised digit rule and cannot round when the number is written in words.

Why: The rule operates on the written form rather than on the value, so an unfamiliar form leaves nothing to apply it to.

Fix: Teach the number line first and the digit shortcut second. The shortcut then has a meaning to fall back on.

If they are not there yet

  • Round two-digit numbers to the nearest ten only, with the number line drawn and labelled.
  • Mark the halfway point on every line so 'nearer' can be judged by eye rather than by calculation.

If they finish early

  • Round four-digit numbers to the nearest thousand.
  • Find all the numbers that round to 500 when rounded to the nearest hundred.
  • Estimate a sum by rounding both numbers first, then compare with the exact answer.

Exit ticket

Round 273 to the nearest ten. Then round it to the nearest hundred.

What to look for: 270 and 300. Both answers matching means one target was used for both; 280 for the first means the halfway convention was applied to the wrong digit.

Printable practice for 3.NBT.A.1

Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.

Questions about Rounding to the Nearest Ten or Hundred

How long does the Rounding to the Nearest Ten or Hundred lesson take?

45 minutes, split across 5 timed sections: warm-up 5 min, teach 14 min, guided practice 12 min, independent practice 11 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.

Which standard does Rounding to the Nearest Ten or Hundred teach?

CCSS.MATH.CONTENT.3.NBT.A.1 — 3.NBT.A.1, Number & Operations in Base Ten for Grade 3: “Use place value understanding to round whole numbers to the nearest 10 or 100.” In plain terms, round numbers to the nearest ten or hundred.

What do I need to teach this lesson?

Number lines marked in tens and in hundreds, number cards, whiteboards and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.

What mistakes should I expect in this lesson?

Three, each a reasoning error rather than carelessness: rounds 347 to 300 when asked for the nearest ten; rounds 96 to the nearest ten as 90 because rounding up 'would change the hundreds' and applies a memorised digit rule and cannot round when the number is written in words. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.

How do I know whether the lesson worked?

The exit ticket asks: “Round 273 to the nearest ten. Then round it to the nearest hundred.” 270 and 300. Both answers matching means one target was used for both; 280 for the first means the halfway convention was applied to the wrong digit. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.

Is there a worksheet to go with Rounding to the Nearest Ten or Hundred?

Yes — 2 printable 3.NBT.A.1 worksheets, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.

Is Rounding to the Nearest Ten or Hundred free to use?

Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 5 September 2026. Please do not resell it or republish it as your own.

Last reviewed 2026-09-05. Aligned to 3.NBT.A.1 of the Common Core State Standards for mathematics.