Library›Addition Fluency›One card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaSum

15 + 15

Think it. Then flip it. ahamoraTap to reveal Back to the cue
Math & LogicOne small aha
Your new aha30

15 + 15 = 30. Changing the order gives 15 + 15, the same sum. Source: Addition ↗

ahamoraReference ↗

Keep the thread going

One answer is a beginning.

Share a little curiosity, or follow it into the full collection.

Flip the full deck →

More from Addition Fluency

A few more worth knowing.

  1. 34715 + 16RECALL
    31

    Mental addition

    Open this card ↗
  2. 34815 + 17RECALL
    32

    Mental addition

    Open this card ↗
  3. 34915 + 18RECALL
    33

    Mental addition

    Open this card ↗