LibraryAddition FluencyOne card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaSum

20 + 27

Think it. Then flip it.
ahamoraTap to reveal
Back to the cue
Math & LogicOne small aha
Your new aha47

20 + 27 = 47. Changing the order gives 27 + 20, 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. 43920 + 28RECALL
    48

    Mental addition

    Open this card ↗
  2. 44020 + 29RECALL
    49

    Mental addition

    Open this card ↗
  3. 44121 + 21RECALL
    42

    Mental addition

    Open this card ↗