Library›Multiplication Fluency›One card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaProduct

15 × 17

Think it. Then flip it. ahamoraTap to reveal Back to the cue
Math & LogicOne small aha
Your new aha255

15 groups of 17 make 255. Reversing the factors, 17 × 15, gives the same product. Source: Multiplication table ↗

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 Multiplication Fluency

A few more worth knowing.

  1. 26415 × 18RECALL
    270

    Mental multiplication

    Open this card ↗
  2. 26515 × 19RECALL
    285

    Mental multiplication

    Open this card ↗
  3. 26615 × 20RECALL
    300

    Mental multiplication

    Open this card ↗