Step by step
The question
Question: There are 2 shirts and 3 pants.
How many outfits can be made with one of each?
1 Count the choices
2 Draw a tree
3 Multiply
Each of the 2 shirts goes with 3 pants.
So we multiply: 2 × 3.
outfits = 2 × 3
This is the counting principle: multiply the number of choices.
counting principle:
multiply the choices
2 groups of 3: that is 2 times 3.
3 + 3 = 2 × 3
Careful!
We do not add the choices.
Every choice goes with every other one, so we multiply.
Careful: not 2 + 3 = 5 ✗
2 times 3 is 6.
2 × 3 = 6
So there are 6 outfits.
outfits = 6
4 Check
Let's check: we count the ends of the tree.
There are 6 ends, one for each.
So the answer is right!
6 ends = 6 outfits
Let's look back.
First: count the choices.
Then: draw a tree.
Then: multiply.
Last: check.
Answer
outfits = 6