Without a calculator, simplify each of the following expressions.

1. $0.25 + 2.5 + 2.5$

   Hint (a):

   Try doing this one without making any calculations on paper. What is $2.5 + 2.5$?

2. $432.7 - 0.08$

   Hint (b):

   Here, you are subtracting $\frac{8}{100} \text{ from }432\frac{70}{100}.$

   Which are like parts?
   Can you find the difference in your head?

   Answer (b):

   $432.62$

3. $4.57 · 0.3$

   Hint (c):

   It might be useful to think of this as $\left(4\frac{57}{100}\right)\left(\frac{3}{10}\right)\text{ or }\left(\frac{457}{100}\right)\left(\frac{3}{10}\right)$

   Answer (c):

   $\frac{(457)(3)}{1000}=\frac{1371}{1000}=1\frac{371}{1000}=1.371$