Math lesson plan · 3rd grade (Year 4 in England) · 45 minutes
Turnaround facts: order does not change a product
Multiplication and division
CCSS 3.OA.B.5England: Y4 Multiplication and division
Objective and success criteria
Students will: Turnaround facts: order does not change a product.
- 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: Write a multiplication sentence for an array
Leads to: Multiply three numbers by regrouping
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 (Write a multiplication sentence for an array). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Ines arranges 36 chairs in 4 equal rows. How many chairs are in each row? → 9Prompt: 4 × ? = 36
- Elena arranges 20 chairs in 4 equal rows. How many chairs are in each row? → 5Prompt: 4 × ? = 20
- Leo arranges 30 chairs in 10 equal rows. How many chairs are in each row? → 3Prompt: 10 × ? = 30
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: Turnaround facts: order does not change a product. 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: 5 × 34 = 170. What is 34 × 5?
- Step 1: 34 × 5 = 5 × 34 = 170
- Answer: 170
- 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.
- 2 × 27 = 54. What is 27 × 2? → 54Prompt: Does changing the order of the numbers change the answer?
- 11 × 19 = 209. What is 19 × 11? → 209Prompt: Does changing the order of the numbers change the answer?
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.
- 8 × 15 = 120. What is 15 × 8? → 120Prompt: Does changing the order of the numbers change the answer?
- 5 × 17 = 85. What is 17 × 5? → 85Prompt: Does changing the order of the numbers change the answer?
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: Write a multiplication sentence for an array.
- 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: Multiply three numbers by regrouping.
- 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