Addition

4 minQuiz at the end

What is Addition?

Addition is the process of combining two or more numbers to find their total (sum).

Symbol: + | Result: sum

Key Properties

Commutative property: a + b = b + a

  • 5 + 3 = 3 + 5 = 8

Associative property: (a + b) + c = a + (b + c)

  • (2 + 3) + 4 = 2 + (3 + 4) = 9

Identity property: a + 0 = a

  • 7 + 0 = 7

Column Addition with Carrying

When digits in a column add up to 10 or more, carry the tens digit to the next column:

  348
+ 275
-----
  623

8 + 5 = 13 β†’ write 3, carry 1 4 + 7 + 1 = 12 β†’ write 2, carry 1 3 + 2 + 1 = 6

Mental Addition Strategies

  • Make 10: 8 + 7 = 8 + 2 + 5 = 10 + 5 = 15
  • Split method: 34 + 28 = 34 + 20 + 8 = 62
  • Round and adjust: 47 + 39 = 47 + 40 - 1 = 86

Word Problems

Clue words for addition: total, altogether, sum, combined, in all, plus, more than.