Multiply: 8*63. You might break up that 63 into two parts: 60 and 3.
Now multiply 8 times 60 and 8 times 3, separately, and then add together the two products:
8*60 = 480
8 * 3 = 24
Sum: 504
This is a good example of mental math, where you use math tricks to do calculations without a calculator.