Doubles and Near-Doubles

Two strategies that turn dozens of addition facts into ones your child can answer instantly.

What we're learning

The "doubles" — facts where both addends are the same (1+1, 2+2, … up to 10+10)
"Near doubles" — facts that are one off from a double (5+6 = 5+5+1)
Why doubles are the easiest facts to memorize, and how to leverage them

The doubles you want known cold

1 + 1 = 2
2 + 2 = 4
3 + 3 = 6
4 + 4 = 8
5 + 5 = 10
6 + 6 = 12
7 + 7 = 14
8 + 8 = 16
9 + 9 = 18
10 + 10 = 20

That's only ten facts. Most first graders can have all of them memorized in a few weeks of daily practice.

The reason to start here: doubles are the easiest addition facts to memorize. The pattern is so visible, the symmetry so satisfying, that the brain hangs onto them readily.

Why near-doubles is the magic move

Once your child knows their doubles, they can compute:

5 + 6 → "5 + 5 = 10, plus 1 more, is 11"
7 + 8 → "7 + 7 = 14, plus 1 more, is 15"
4 + 5 → "4 + 4 = 8, plus 1 more, is 9"

This single trick covers every "consecutive numbers" addition fact. Combined with doubles, it knocks out a meaningful chunk of the addition table.

Try it together

Mirror hands. Show them both your hands with 4 fingers up on each. "How many?" They count or just see: 8. Practice with all the doubles you can show on hands.
Domino doubles. A standard double-six domino set has dominos with both halves matching: 0+0, 1+1, 2+2, …, 6+6. Sort those out. Use them as flashcards.
The "+1 trick." Show two dice. "Are these the same number? No? Are they one apart?" If yes, double the smaller and add one — or double the larger and subtract one. Either works.

Watch for

Memorizing without understanding what doubling means. A child who recites "8 + 8 = 16" but can't tell you that 16 is two groups of 8 has memorized a sound, not a fact. Periodically ask: "Show me 8 + 8 with cookies." If they line up two rows of 8 and say "16," you're good.
Skipping the near-doubles trick. Some children, once they learn it, decide it's "for babies" and refuse to use it. The trick is genuinely fast and doesn't go away — pros use this exact strategy for arithmetic in their head as adults. Frame it as a grown-up shortcut.

Where this is going

After doubles and near-doubles, the last big strategy in this layer is "make a ten" — the single most powerful technique in single-digit addition. Bonds to 10 (the bridge for making a ten) is the prerequisite, so that lesson comes next in our sequence.