Math lesson plan · 4th grade (Year 5 in England) · 45 minutes
Multiply two-digit numbers with an area model
Multiplication and division
CCSS 4.NBT.B.5England: Y5 Multiplication and division
Objective and success criteria
Students will: Multiply two-digit numbers with an area model.
- 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: Break apart a multiplication (distributive property); Multiply multiples of 10, 100 and 1000 mentally
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 (Break apart a multiplication (distributive property); Multiply multiples of 10, 100 and 1000 mentally). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 900 × 50 = ? → 45000Prompt: Start with the basic fact 9 × 5.
- 20 × 600 = ? → 12000Prompt: Start with the basic fact 2 × 6.
- 70 × 3 = ? → 210Prompt: Start with the basic fact 7 × 3.
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: Multiply two-digit numbers with an area model. 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: For 36 × 18, the area model has four parts: 30 × 10 = 300, 30 × 8 = ?, 6 × 10 = 60, 6 × 8 = 48. What is the missing part?
- Step 1: 30 × 8 = 240
- Answer: 240
- 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.
- For 22 × 29, the area model has four parts: 20 × 20 = 400, 20 × 9 = 180, 2 × 20 = ?, 2 × 9 = 18. What is the missing part? → 40Prompt: Each part is one piece of the first number times one piece of the second.
- Use an area model to work out 26 × 27. → 702Prompt: Split into 20 + 6 and 20 + 7.
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.
- For 48 × 48, the area model has four parts: 40 × 40 = 1600, 40 × 8 = ?, 8 × 40 = 320, 8 × 8 = 64. What is the missing part? → 320Prompt: Each part is one piece of the first number times one piece of the second.
- Use an area model to work out 31 × 28. → 868Prompt: Split into 30 + 1 and 20 + 8.
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: Break apart a multiplication (distributive property).
- 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-4.
Free lesson plan from eurekami.com/lesson-plan-builder