Math lesson plan · 5th grade (Year 6 in England) · 45 minutes
Estimate to check multi-digit calculations
Multiplication and division
CCSS 5.NBT.B.5England: Y6 Number and place value
Objective and success criteria
Students will: Estimate to check multi-digit calculations.
- 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: Estimate products by rounding
Leads to: the next skill in this area.
Materials: Counters for arrays, Multiplication grid, Base-ten blocks, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Estimate products by rounding). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Estimate 943 × 6 by rounding 943 to the nearest hundred. → 5400Prompt: 943 rounds to what?
- Which is the best estimate for 36 × 61? (24 000 / 2400 / 100 / 1500) → 2400Prompt: Round each number to the nearest ten.
- Ethan's calculator shows 518 × 5 = 2590. Use an estimate: is that answer reasonable? (Yes, it is close to the estimate / No, it is far from the estimate) → Yes, it is close to the estimatePrompt: Round 518 to the nearest hundred.
Hook · 5 min
- Show an array of chairs, eggs or windows and ask how many there are without counting one by one.
- Share the objective: Estimate to check multi-digit calculations. 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: Estimate 964 × 28 by rounding 964 to the nearest hundred and 28 to the nearest ten.
- Step 1: 964 ≈ 1000, 28 ≈ 30
- Step 2: 1000 × 30 = 30 000
- Answer: 30000
- 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.
- Estimate 830 × 47 by rounding 830 to the nearest hundred and 47 to the nearest ten. → 40000Prompt: Round each number first.
- Without dividing exactly, which is the best estimate for 78 021 ÷ 9? (14 000 / 90 000 / 9000 / 900) → 9000Prompt: Round 78 021 to something easy to divide by 9.
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.
- Estimate 337 × 76 by rounding 337 to the nearest hundred and 76 to the nearest ten. → 24000Prompt: Round each number first.
- Without dividing exactly, which is the best estimate for 18 081 ÷ 3? (60 000 / 11 000 / 6000 / 600) → 6000Prompt: Round 18 081 to something easy to divide by 3.
Watch out for
- Thinking multiplying always makes a number bigger.
- Dropping a zero in long multiplication when moving to the tens row.
Support and stretch
Support
- Review first: Estimate products by rounding.
- Use concrete materials: counters for arrays.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- 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-5.
Free lesson plan from eurekami.com/lesson-plan-builder