Math lesson plan · 4th grade (Year 5 in England) · 45 minutes
Estimate products by rounding
Multiplication and division
CCSS 4.OA.A.3CCSS 4.NBT.B.5England: Y5 Number and place value
Objective and success criteria
Students will: Estimate products by rounding.
- 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: Multiply multiples of 10, 100 and 1000 mentally; Round multi-digit numbers
Leads to: Estimate to check multi-digit calculations; Divide three-digit numbers by two-digit numbers
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 (Multiply multiples of 10, 100 and 1000 mentally; Round multi-digit numbers). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 500 × 80 = ? → 40000Prompt: Start with the basic fact 5 × 8.
- Round 188 195 to the nearest 10 000. → 190000Prompt: Which two multiples of 10 000 is it between?
- 40 × 5 = ? → 200Prompt: 4 × 5 = 20. Careful: this fact already ends in a zero.
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 products by rounding. 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 538 × 5 by rounding 538 to the nearest hundred.
- Step 1: 538 ≈ 500
- Step 2: 500 × 5 = 2500
- Answer: 2500
- 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 228 × 5 by rounding 228 to the nearest hundred. → 1000Prompt: 228 rounds to what?
- Which is the best estimate for 58 × 61? (360 / 3600 / 36 000 / 2500) → 3600Prompt: Round each number to the nearest ten.
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.
- Ava's calculator shows 771 × 4 = 3084. 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 771 to the nearest hundred.
- Estimate 266 × 5 by rounding 266 to the nearest hundred. → 1500Prompt: 266 rounds to what?
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: Multiply multiples of 10, 100 and 1000 mentally.
- 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
- Move on to: Estimate to check multi-digit calculations; Divide three-digit numbers by two-digit numbers.
- 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-4.
Free lesson plan from eurekami.com/lesson-plan-builder