Library›Subtraction Fluency›One card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaDifference

20 − 11

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

20 − 11 = 9. The difference tells you the gap between 11 and 20. 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. 22120 − 10RECALL
    10

    Mental subtraction

    Open this card ↗
  2. 22220 − 9RECALL
    11

    Mental subtraction

    Open this card ↗
  3. 22320 − 8RECALL
    12

    Mental subtraction

    Open this card ↗