The Vitruvian Man Method
A fixed body motion for the bridge method, so that a lapse in the middle of a calculation has an obvious place to restart from.
1. Why you need it
The bridge method is fast but it has three columns, and under exam pressure the failure mode is not a wrong digit — it is forgetting which column you were on. The Vitruvian Man method turns the three columns into three physical positions: right arm (last × last), both arms crossing (the cross terms), left arm (first × first). Same arithmetic, but the sequence is anchored to the body, so restarting costs nothing.
Fixed path: 23 × 41
Right arm: 3 × 1 = 3 → write 3. Two arms crossing: 2 × 1 + 3 × 4 = 2 + 12 = 14 → write 4, carry 1. Left arm: 2 × 4 = 8, plus carry = 9. Answer 943.
2. The finger walk
- Touch the right-hand pair of digits, say the product out loud, write it down.
- Cross both hands over the middle: add the two cross products, resolve the carry.
- Touch the left-hand pair, add any carry, write the leading digits.
- If you lose the thread, do not recompute — repeat the last position you can name and continue from there.
After a week of practice, all three columns happen without the hand movements; the movement is scaffolding, not the method.
3. Practice
- 23 × 41 with the three positions
- 34 × 21
- 42 × 13
- 31 × 14
- Invent three of your own and compute them with the fixed path only
Answers
Once the multiplier has three or more digits, switch to the UT method →
Previous lesson: The Bridge Method