Math lesson plan · 4th grade (Year 5 in England) · 60 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 · 6 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 × 800 = ? → 400000Prompt: Start with the basic fact 5 × 8.
- Round 2181 to the nearest 100. → 2200Prompt: Which two multiples of 100 is it between?
- 50 × 5 = ? → 250Prompt: 5 × 5 = 25. Careful: this fact already ends in a 5.
Hook · 6 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 · 12 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 · 12 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 157 × 4 by rounding 157 to the nearest hundred. → 800Prompt: 157 rounds to what?
- Which is the best estimate for 22 × 88? (110 / 18 000 / 1800 / 800) → 1800Prompt: Round each number to the nearest ten.
You do: independent practice · 17 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 · 7 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Which is the best estimate for 77 × 49? (2800 / 400 / 40 000 / 4000) → 4000Prompt: Round each number to the nearest ten.
- Estimate 752 × 5 by rounding 752 to the nearest hundred. → 4000Prompt: 752 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