Chapter 4.5, Problem 4P

For each of the multiplication problems (a) through (c), describe a way to make the problem easy to solve mentally. Then write equations that correspond to your method of calculation. Write your equations in the following form:

   $\begin{array}{l}24.25=someexpression\hfill \\ =someexpression\hfill \\ =.:\hfill \end{array}$

In each case, state which properties of arithmetic you used, and indicate where you used those properties.

a. $24\cdot 25$

b. $25\cdot 48$

c. $51\cdot 6$