Decimal Operations: example 5.16

Multiply: $(−8.2) (5.19).$

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Multiply: $(4.63) (−2.9) .$

How did it go?

	$(−8.2) (5.19)$
The signs are different.	The product will be negative.
Write in vertical format, lining up the numbers on the right.	$\begin{matrix} 5.19 \\ \underset{_____}{\times 8.2} \end{matrix}$
Multiply.	$\begin{matrix} 5.19 \\ \underset{_____}{\times 8.2} \\ 1038 \\ \underset{_____}{4152} \\ 42558 \end{matrix}$
	$\begin{matrix} 5.19 \\ \underset{_____}{\times 8.2} \\ 1038 \\ \underset{_____}{4152} \\ 42.558 \end{matrix}$
The product is negative.	$(−8.2) (5.19) = −42.558$

	$(−8.2) (5.19)$
The signs are different.	The product will be negative.
Write in vertical format, lining up the numbers on the right.	$\begin{matrix} 5.19 \\ \underset{_____}{\times 8.2} \end{matrix}$
Multiply.	$\begin{matrix} 5.19 \\ \underset{_____}{\times 8.2} \\ 1038 \\ \underset{_____}{4152} \\ 42558 \end{matrix}$
	$\begin{matrix} 5.19 \\ \underset{_____}{\times 8.2} \\ 1038 \\ \underset{_____}{4152} \\ 42.558 \end{matrix}$
The product is negative.	$(−8.2) (5.19) = −42.558$