Library›Addition Fluency›One card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaSum

1 + 8

Think it. Then flip it. ahamoraTap to reveal Back to the cue
Math & LogicOne small aha
Your new aha9

1 + 8 = 9. Changing the order gives 8 + 1, 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. 192 + 2RECALL
    4

    Mental addition

    Open this card ↗
  2. 202 + 3RECALL
    5

    Mental addition

    Open this card ↗
  3. 212 + 4RECALL
    6

    Mental addition

    Open this card ↗