3 ms·
I remember reading how Bethe taught Feynman how to square numbers around 50 in his head. 1) Start at 50^2 = 2500. 2) Pick a number, determine how far away it i
by tvchurch 17y ago
I remember reading how Bethe taught Feynman how to square numbers around 50 in his head.
1) Start at 50^2 = 2500.
2) Pick a number, determine how far away it is from 50, call it N (N can be negative).
3) Multiply N by 100, add that number to 2500.
4) Square N, add that number to your current total.
For example, 52^2.
1) Start at 2500.
2) N = 2.
3) N100 = 200. 2500 + 200 = 2700.
4) N^2 = 4. 2700 + 4 = 2704.
Example when N is negative: 47^2.
1) Start at 2500.
2) N = -3.
3) N100 = -300. 2500 + (-300) = 2200.
4) N^2 = 9. 2200 + 9 = 2209.