Decimal Operations: example 5.11

Add: $3.7 + 12.4 .$

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.

Add: $5.7 + 11.9 .$

How did it go?

	$3.7 + 12.4$
Write the numbers vertically so the decimal points line up.	$\begin{matrix} 3.7 \\ \underset{_____}{+ 12.4} \end{matrix}$
Place holders are not needed since both numbers have the same number of decimal places.
Add the numbers as if they were whole numbers. Then place the decimal in the answer under the decimal points in the given numbers.	$\begin{matrix} \overset{1}{3} . 7 \\ \underset{_____}{+ 12.4} \\ 16.1 \end{matrix}$

	$3.7 + 12.4$
Write the numbers vertically so the decimal points line up.	$\begin{matrix} 3.7 \\ \underset{_____}{+ 12.4} \end{matrix}$
Place holders are not needed since both numbers have the same number of decimal places.
Add the numbers as if they were whole numbers. Then place the decimal in the answer under the decimal points in the given numbers.	$\begin{matrix} \overset{1}{3} . 7 \\ \underset{_____}{+ 12.4} \\ 16.1 \end{matrix}$