The question
Question: which property is this: 3 + 5 = 5 + 3?
3 + 5 = 5 + 3
1 Compare the two sides
Look at both sides.
The order changed.
the order changed
So it is the commutative property of addition.
= commutative property of addition
2 Check
Let's check: work out both sides.
The left side is 8.
The right side is 8.
Both the same.
So the answer is right!
3 + 5 = 8, 5 + 3 = 8
Let's look back.
First: compare the two sides.
Last: check.
Answer = commutative property of addition
▶ Watch it solved
The question
Question: which property is this: (2 + 3) + 4 = 2 + (3 + 4)?
(2 + 3) + 4 = 2 + (3 + 4)
1 Compare the two sides
Look at both sides.
The brackets moved.
the brackets moved
So it is the associative property of addition.
= associative property of addition
2 Check
Let's check: work out both sides.
The left side is 9.
The right side is 9.
Both the same.
So the answer is right!
(2 + 3) + 4 = 9, 2 + (3 + 4) = 9
Let's look back.
First: compare the two sides.
Last: check.
Answer = associative property of addition
▶ Watch it solved
The question
Question: write 24 + 36 as a product, using the biggest common factor.
24 + 36
1 Find the GCF
A factor of 24 is a whole number that goes into 24 exactly.
Nothing is left over.
The factors of 24: 1, 2, 3, 4, 6, 8, 12, 24.
The factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36.
24: 1, 2, 3, 4, 6, 8, 12, 24
36: 1, 2, 3, 4, 6, 9, 12, 18, 36
The biggest number in both lists is 12.
= GCF = 12
2 Take it out
24 is 12 times 2.
36 is 12 times 3.
= 12 × 2 + 12 × 3
Both parts have times 12.
So we take the 12 out, in front of a bracket: 12(2 + 3).
This is the distributive property, backwards.
= 12(2 + 3)
Careful!
We need the brackets.
Without them, the 12 times only the 2.
Careful: not 12 × 2 + 3 ✗
3 Check
Let's check: 12 times 5 is 60.
And 24 plus 36 is 60.
The same.
So the answer is right!
12 × 5 = 60 and 24 + 36 = 60
Let's look back.
First: find the GCF.
Then: take it out.
Last: check.
Answer Careful: not 12 × 2 + 3 ✗
▶ Watch it solved
