Grade 4 · Maths · Lessons
Follow the rule, then spot something
📜rule🔢pattern🔍spot🧩why
Follow the rule.The big ideaFollow the rule. Then look for what the rule never said.
How it works
Follow the rule to write the next terms. Then look for what the rule never said.
Start at 23 and take away 2: 21, 19, 17. Every term is odd.
Say why: taking away an even number keeps an odd number odd.
Example 1: Run the rule
- Start at 23. Subtract 2. Write the next three terms.
- Subtract 2 each time.
- 23 − 2 = 21, 21 − 2 = 19, 19 − 2 = 17.
- So the answer is (21, 19, 17).
Example 2: Spot something
- Start at 7 and add 2: 7, 9, 11, 13.
- Every term is odd.
- Adding 2, an even number, keeps an odd number odd.
Example 3: Will it be there?
- Start at 47. Add 2. Will 75 be in the pattern?
- The rule is add 2 from 47, and every term is odd.
- 75 is odd, so it can be reached.
- So the answer is Yes. Every term is odd, and 75 is odd..
Words to know
- rule
- A step you repeat to make a pattern.
- term
- One number in a pattern.
Watch out
- Follow the rule exactly.
- Look for features the rule didn't say, like odd or even.
- Explain why the feature happens.
Try it
- Start at 5 and add 3. Write the next three terms.
- Start at 20 and subtract 5. Next three?
- Start at 2 and add 2. Are all terms even?
- Start at 1 and add 2. Will 10 be there?
Answers: 1. 8, 11, 14 · 2. 15, 10, 5 · 3. yes · 4. no
For grown-upsMake up a rule and ask your child to continue the pattern and spot what is always true.