Math lesson plan · 4th grade (Year 5 in England) · 45 minutes
Factors, multiples, primes
Number sense
CCSS 4.OA.B.4England: Y5 Multiplication and division
Objective and success criteria
Students will: Factors, multiples, primes.
- 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: Times tables to 12 × 12
Leads to: Primes, squares and cubes; Greatest common factor and least common multiple; Add and subtract fractions with unlike denominators
Materials: Place value chart, Base-ten blocks or a number line, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Times tables to 12 × 12). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 10 × 6 = ? → 60Prompt: Is there a fact you already know that is close?
- __ × 7 = 21 → 3Prompt: Which number in the 7 times table gives 21?
- Which of these is 9 × 9? (81 / 90 / 18 / 91) → 81Prompt: Use a fact you know and adjust.
Hook · 5 min
- Show a number in the news or a price tag and ask what each digit is worth.
- Share the objective: Factors, multiples, primes. 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: Which number is a factor of 54?
- Step 1: 54 ÷ 9 = 6
- Step 2: So 9 is a factor of 54.
- Answer: 9
- 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.
- Which number is a factor of 18? (11 / 7 / 6 / 5) → 6Prompt: A factor divides the number exactly, with no remainder.
- Is 11 prime or composite? (Prime / Composite) → PrimePrompt: A prime number has exactly two factors: 1 and itself.
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 is the 11th multiple of 6? (The 1st multiple is 6.) → 66Prompt: Multiples of 6: 6, 12, 18, …
- Is 17 prime or composite? (Prime / Composite) → PrimePrompt: A prime number has exactly two factors: 1 and itself.
Watch out for
- Reading 1,045 as one thousand four hundred five: point to each place and say its value.
- Thinking a longer number is always bigger, even with decimals (0.45 vs 0.5).
Support and stretch
Support
- Review first: Times tables to 12 × 12.
- Use concrete materials: place value chart.
- 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: Primes, squares and cubes; Greatest common factor and least common multiple; Add and subtract fractions with unlike denominators.
- 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