Adding is fun and understanding addition involves combining addends to get a sum. The example given is 2 + 3 = 5 where 2 and 3 are the addends that combine to make the sum of 5. Another example shown is 1 + 4 = 5, demonstrating the concept of addition through number combinations in an equation with the words plus and equals.

1. Adding is fun!

2. Understanding Addition 2 3 = 5 + addend addend sum

3. Number Combinations 1 4 = 5 + Addition Sentence plus equals