Week 04 · Factors, multiples and patterns
Monday
Factor pairs
// Factor pairs, primes and number rules
⏱ about 15 min
Monday: Factor pairs
Samantha the Squirrel bounds down the oak tree with her cheeks full.
"I gathered 24 acorns!" she says, dropping them in a heap.
"I want to line them up in rows to dry, with the same number in every row."
She makes 4 rows of 6. Then she tries 3 rows of 8.
"Wait, both ways work!" she squeaks, her bushy tail twitching.
Bennie the Bear nods. "Each way is a factor pair of 24."
"Let us find every way to make rows."
Learn it: factor pairs make rectangles
4 rows of 6 acorns make 24, because 4 × 6 = 24.
4 and 6 are factors of 24. Together they are a factor pair.
The factor pairs of 24 are 1 × 24, 2 × 12, 3 × 8, 4 × 6.
So the factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24.
Start with 1 and count up. Stop when the pairs start to repeat.
FIND A FACTOR PAIR
- Read the question.
- Tap your answer.
Which is a factor pair of 24?
Which is a factor pair of 36?
Which is a factor pair of 18?
Which is a factor pair of 40?
FIND THE MISSING FACTOR
- Read the question.
- Tap your answer.
3 × ? = 24
? × 9 = 36
6 × ? = 54
? × 7 = 56
ALL THE FACTORS
- Read the question.
- Tap your answer.
Which list shows all the factors of 12?
Which list shows all the factors of 20?
How many factors does 16 have?
How many factors does 30 have?
FACTOR PAIRS OF 24, IN ORDER
- Start with 1 as the first factor.
- Tap the factor pairs in order.
11st
22nd
33rd
44th
A factor divides the number with nothing left over.
| Sentence | True or false? |
|---|---|
| 4 × 6 = 24 | ? |
| 5 × 5 = 24 | ? |
| 7 is a factor of 24. | ? |
| 3 is a factor of 24. | ? |
WHY THIS EXERCISE24 ÷ 7 leaves a remainder of 3, so 7 is not a factor.
Try it
Count out 12 small things, like beans or buttons.
Arrange them in equal rows.
How many different ways can you make rows?
Write each way as a factor pair.
Arrange them in equal rows.
How many different ways can you make rows?
Write each way as a factor pair.
Draw two different rectangles made of 24 squares.
Great factoring! Tomorrow we explore multiples.