Mentally calculate the following products. Use the rule for decimal multiplication to write an equation in which the decimal point is written in the correct location.  

1. $(-0.04)(-0.1)$ 

   Hint 1:

   Think: A small number times a small number is a ____ number.

   Hint 2:

   A negative number times a negative number is a _____ number.

   Step (a):

   Multiply $(4)(1)$ and move the decimal three places to the left.

2. $(0.03)(-0.02)$ 

   Answer:

   $-0.0006$

3. $(0.7)(0.4)$ 

   Hint (c):

   See part (a).

4. Stacey said, “Stephanie, look at my answer to the last problem, $0.7·0.4=0.28$. Usually when I multiply, I get a bigger answer than the numbers I start with. Twenty-eight hundredths, $\mathit{0.28}$, is less than either $\mathit{0.4}$ or $\mathit{0.7}$. I must have made a mistake.”

   Stephanie responded, “Well, one half times one half is one fourth, and one fourth is less then one half. I think when you multiply by a fraction or decimal less than one, you get less than you started with.”

   Write a sentence or two about who you think is correct and why.

   Answer (d):

   Stephanie is correct. Why?