Build from a known fact FAQs

Answers about Build from a known fact speed sheets, including when to use the shortcut and what to practice next.

What is a Build from a known fact mental math speed sheet?

It is a timed grid of 50 multiplication problems in 5 minutes, all built for the Build from a known fact shortcut. Example pattern: 7 × 8 → 7 × 10 = 70, then take two 7s: 70 − 14 = 56.

Should I try the Build from a known fact speed sheet first?

Learn the trick first at https://www.besparq.com/learn/mental-math/build-from-a-known-fact/learn, then warm up with flashcards at https://www.besparq.com/learn/mental-math/build-from-a-known-fact/flashcards. The speed sheet is for fluency after the strategy makes sense.

How is a 50-in-5 sheet different from a worksheet?

You type answers in a grid against a 5-minute timer and see a score when you submit. Missed Build from a known fact items stay visible so you can retry the same shortcut.

Can I retry the Build from a known fact speed sheet?

Yes. Start another 50-problem sheet anytime. Use a slower flashcard pass if the timer still feels rushed.

Where are the other mental math strategies?

All 15 strategies plus multiplication facts live on the Mental Math hub at https://www.besparq.com/learn/mental-math.