1. What is the difference between the greatest and the least of the following five quantities?
$$
20+20 \quad 20 \times 20 \quad 202+0 \quad\left(2^{0}\right)^{\left(2^{0}\right)} \quad 20+2+0
$$
SolUtion
399

The five quantities are $40,400,202,1^{1}=1$ and 22 .
The difference between the greatest and least of these is $400-1=399$.