Doubles Addition Facts

What a double means

A double is an addition fact where both addends are the same, such as (3+3) or (8+8). Instead of counting two different numbers, you are finding two equal groups together.

Method

1. Read the number once. If the problem is (n+n), focus on (n).
2. Think of it as two copies of the same amount. For example, (5+5) means 2 groups of 5.
3. Use a strategy you know:
   • count on from the first number,
   • use fingers or objects,
   • or recall the double from memory.
4. Write the total.

Helpful patterns

Some doubles are easy to remember:

• (1+1=2)
• (2+2=4)
• (3+3=6)
• (4+4=8)
• (5+5=10)

If the numbers are larger, keep the same idea: (7+7=14), (9+9=18).

Check your answer

Make sure the two addends are exactly the same. Then verify by counting forward from one addend by that same number, or by thinking of doubling a set of objects.