Math lesson plan · 3rd grade (Year 4 in England) · 45 minutes
Find the unknown in multiplication and division equations
Multiplication and division
CCSS 3.OA.A.4England: Y3 Multiplication and division
Objective and success criteria
Students will: Find the unknown in multiplication and division equations.
- 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: Multiplication and division fact families
Leads to: Solve equations with a letter for the unknown
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 (Multiplication and division fact families). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which fact belongs in the same family as 4 × 5 = 20? (4 + 5 = 9 / 20 − 4 = 16 / 20 ÷ 5 = 5 / 20 ÷ 5 = 4) → 20 ÷ 5 = 4Prompt: A fact family uses the same three numbers: 4, 5 and 20.
- Given 6 × 3 = 18, what is 18 ÷ 3? → 6Prompt: Division undoes multiplication.
- Which fact belongs in the same family as 4 × 10 = 40? (40 ÷ 5 = 10 / 40 ÷ 4 = 10 / 4 + 10 = 14 / 40 − 4 = 36) → 40 ÷ 4 = 10Prompt: A fact family uses the same three numbers: 4, 10 and 40.
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: Find the unknown in multiplication and division equations. 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: What number does ▢ stand for? 30 = ▢ × 10
- Step 1: 30 = 3 × 10
- Step 2: 3
- Answer: 3
- 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.
- What number does ▢ stand for? 60 = ▢ × 6 → 10Prompt: Read the equation as a sentence: what times or divided by what?
- Daniel thinks of a number and multiplies it by 8. The answer is 64. What was the number? → 8Prompt: Write it as ▢ × 8 = 64.
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.
- What number does ▢ stand for? ▢ ÷ 6 = 10 → 60Prompt: Read the equation as a sentence: what times or divided by what?
- Ethan thinks of a number and multiplies it by 3. The answer is 18. What was the number? → 6Prompt: Write it as ▢ × 3 = 18.
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: Multiplication and division fact families.
- 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: Solve equations with a letter for the unknown.
- 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