  ### Home > CC2 > Chapter 3 > Lesson 3.2.4 > Problem3-74

3-74.

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. $(-0.04)(-0.1)$

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

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

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

1. $(0.03)(-0.02)$

$-0.0006$

1. $(0.7)(0.4)$

See part (a).

1. 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.

Stephanie is correct. Why?