LibraryAddition FluencyOne card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaSum

5 + 10

Think it. Then flip it.
ahamoraTap to reveal
Back to the cue
Math & LogicOne small aha
Your new aha15

5 + 10 = 15. Changing the order gives 10 + 5, 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. 875 + 11RECALL
    16

    Mental addition

    Open this card ↗
  2. 885 + 12RECALL
    17

    Mental addition

    Open this card ↗
  3. 895 + 13RECALL
    18

    Mental addition

    Open this card ↗