Math lesson plan · 3rd grade (Year 4 in England) · 45 minutes
Round to the nearest 10 or 100
Number sense
CCSS 3.NBT.A.1England: Y3 Number and place valueEngland: Y4 Number and place value
Objective and success criteria
Students will: Round to the nearest 10 or 100.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Hundreds, tens and ones
Leads to: Round multi-digit numbers; Estimate sums and differences; Round decimals
Materials: Place value chart, Base-ten blocks or a number line, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Hundreds, tens and ones). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- What is the value of the digit 1 in 211? → 10Prompt: Which place is the digit in: hundreds, tens or ones?
- Write as a number: 300 + 20 + 5 → 325Prompt: Each part fills one place: hundreds, tens, ones.
- What is the value of the digit 8 in 298? → 8Prompt: Which place is the digit in: hundreds, tens or ones?
Hook · 5 min
- Show a number in the news or a price tag and ask what each digit is worth.
- Share the objective: Round to the nearest 10 or 100. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Which number rounds to 30 when rounded to the nearest 10?
- Step 1: 26 is nearest to 30.
- Step 2: 26
- Answer: 26
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Which number rounds to 80 when rounded to the nearest 10? (91 / 75 / 74) → 75Prompt: Numbers from 75 up to 84 round to 80.
- Which number rounds to 90 when rounded to the nearest 10? (95 / 101 / 89) → 89Prompt: Numbers from 85 up to 94 round to 90.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Which number rounds to 20 when rounded to the nearest 10? (15 / 31 / 25) → 15Prompt: Numbers from 15 up to 24 round to 20.
- Which number rounds to 80 when rounded to the nearest 10? (74 / 75 / 91) → 75Prompt: Numbers from 75 up to 84 round to 80.
Watch out for
- Reading 1,045 as one thousand four hundred five: point to each place and say its value.
- Thinking a longer number is always bigger, even with decimals (0.45 vs 0.5).
Support and stretch
Support
- Review first: Hundreds, tens and ones.
- Use concrete materials: place value chart.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Round multi-digit numbers; Estimate sums and differences; Round decimals.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-3.
Free lesson plan from eurekami.com/lesson-plan-builder