Library›Addition Fluency›One card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaSum

4 + 16

Think it. Then flip it. ahamoraTap to reveal Back to the cue
Math & LogicOne small aha
Your new aha20

4 + 16 = 20. Changing the order gives 16 + 4, 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. 1524 + 17RECALL
    21

    Mental addition

    Open this card ↗
  2. 1534 + 18RECALL
    22

    Mental addition

    Open this card ↗
  3. 1544 + 19RECALL
    23

    Mental addition

    Open this card ↗