Subtract Whole Numbers: example 1.31

Subtract and then check by adding: $89 - 61 .$

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.

Subtract and then check by adding: $86 - 54 .$

How did it go?

Write the numbers so the ones and tens digits line up vertically.	$\begin{matrix} 89 \\ \underset{____}{- 61} \end{matrix}$
Subtract the digits in each place value. Subtract the ones: $9 - 1 = 8$ Subtract the tens: $8 - 6 = 2$	$\begin{matrix} 89 \\ \underset{____}{- 61} \\ 28 \end{matrix}$
Check using addition. $\begin{matrix} 28 \\ \underset{____}{+ 61} \\ 89 \end{matrix}$

Write the numbers so the ones and tens digits line up vertically.	$\begin{matrix} 89 \\ \underset{____}{- 61} \end{matrix}$
Subtract the digits in each place value. Subtract the ones: $9 - 1 = 8$ Subtract the tens: $8 - 6 = 2$	$\begin{matrix} 89 \\ \underset{____}{- 61} \\ 28 \end{matrix}$
Check using addition. $\begin{matrix} 28 \\ \underset{____}{+ 61} \\ 89 \end{matrix}$