You know how many are in a group. When two groups are put together, they make one bigger group. That is adding.
Key idea
Adding means putting groups together and finding how many in all. We write $3 + 2 = 5$ and say “3 plus 2 equals 5.”
Why it works
When the groups join, nothing is lost and nothing new comes. So counting everything together tells how many in all.
Worked example: How many balloons?
3 red balloons and 2 blue balloons. How many balloons in all?
- Put the groups together.
- Count them all: 1, 2, 3, 4, 5.
- $3 + 2 = 5$
Answer: 5 balloons
For grown-ups: Use small toys: make two groups, push them together and ask, “How many in all?” Say the words “3 and 2 make 5.”