How to Calculate Faster than a Calculator - Mental Math #1, by Brain Station on YouTube. 5 min 5 s.
- Video length
- 5 min 5 s
- Time to do it
- 15 minutes
- Difficulty
- Easy
- Steps
- 8
What you need
Steps
Write down a two-digit multiplication such as 23 x 14 so you can see both numbers clearly.
Split each number into tens and ones. For 23 x 14 that gives 20 and 3, and 10 and 4.
Multiply the tens parts: 20 x 10 = 200. Keep this running total.
Multiply the outer pair and the inner pair: 20 x 4 = 80 and 3 x 10 = 30. Add both to the total to get 310.
Multiply the ones parts: 3 x 4 = 12. Add it to the total to get 322.
Check your answer with a rough estimate. 23 x 14 is close to 20 x 15 = 300, so 322 is reasonable.
Repeat with five more two-digit pairs, writing each step until the pattern feels automatic.
Once the written steps feel easy, do the same sums in your head and say the answer out loud.
Tips and common mistakes
Break numbers into tens and ones every time. It keeps the sums small and easy to hold in your head.
Estimate first so you can catch a wrong answer before you trust it.
Practice in short daily sessions of five sums rather than long cramming.
Questions
Do I need to memorise times tables first?
Yes, at least up to 10. The method relies on quick single-digit multiplication, so shaky tables will slow you down.
Does this work for numbers over 100?
The same splitting idea works, but you get more parts to add. Start with two-digit numbers until the steps feel natural.
How long until I get faster?
Most people notice a difference after a week of daily practice with five to ten sums.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
