Math lesson plan · 5th grade (Year 6 in England) · 45 minutes
Long multiplication: three-digit by two-digit
Multiplication and division
CCSS 5.NBT.B.5England: Y5 Multiplication and divisionEngland: Y6 Multiplication and division
Objective and success criteria
Students will: Long multiplication: three-digit by two-digit.
- 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 two-digit by two-digit numbers; Multiply a three-digit number by a one-digit number
Leads to: Long multiplication: four-digit by two-digit; Multi-step problems with larger 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 two-digit by two-digit numbers; Multiply a three-digit number by a one-digit number). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 347 × 2 = ? → 694Prompt: Multiply the hundreds, tens and ones separately.
- Use long multiplication: 71 × 42 → 2982Prompt: Multiply 71 by the ones digit of 42.
- 442 × 9 = ? → 3978Prompt: Multiply the hundreds, tens and ones separately.
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: Long multiplication: three-digit by two-digit. 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: 157 × 48 = ?
- Step 1: 157 × 8 = 1256
- Step 2: 157 × 40 = 6280
- Step 3: 1256 + 6280 = 7536
- Answer: 7536
- 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.
- 223 × 38 = ? → 8474Prompt: Multiply 223 by the ones digit of 38, then by the tens.
- A farm packs 144 boxes of strawberries with 12 strawberries in each box. How many strawberries is that? → 1728Prompt: Work out 144 × 12.
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.
- A farm packs 543 boxes of strawberries with 34 strawberries in each box. How many strawberries is that? → 18462Prompt: Work out 543 × 34.
- Fatima worked out 353 × 49 and got 4589. Fatima forgot that the second row is 353 × 40, not 353 × 4. What is the correct answer? → 17297Prompt: The tens row needs a zero placeholder.
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 two-digit by two-digit numbers.
- 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: Long multiplication: four-digit by two-digit; Multi-step problems with larger 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-5.
Free lesson plan from eurekami.com/lesson-plan-builder