LibrarySubtraction FluencyOne card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaDifference

21 − 0

Think it. Then flip it.
ahamoraTap to reveal
Back to the cue
Math & LogicOne small aha
Your new aha21

21 − 0 = 21. The difference tells you the gap between 0 and 21. Source: Subtraction

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 Subtraction Fluency

A few more worth knowing.

  1. 25422 − 22RECALL
    0

    Mental subtraction

    Open this card ↗
  2. 25522 − 21RECALL
    1

    Mental subtraction

    Open this card ↗
  3. 25622 − 20RECALL
    2

    Mental subtraction

    Open this card ↗