Learn how to add and subtract decimals in a few simple steps.
Step by step guide to add and subtract decimals
- Line up the numbers.
- Add zeros to have the same number of digits for both numbers if necessary.
- Add or subtract using column addition or subtraction.
Example 1:
Add. \(1.5 \ + \ 2.14=\)
Solution:
First line up the numbers: \(\begin{array}{r} &1.5\\ +\!\!\!\!\!\!&2.14\\ \hline \end{array}→ \) Add zeros to have same number of digits for both numbers. \(\begin{array}{r} &1.50\\ +\!\!\!\!\!\!&2.14\\ \hline \end{array} \), Start with the hundredths place. \(0 \ + \ 4=4\), \(\begin{array}{r} &1.50\\ +\!\!\!\!\!\!&2.14 \\ \hline \end{array} \\ \ \ \ \ \ \ \ \ \ \ 4\) , Continue with tenths place. \(5 \ + \ 1=6\), \(\begin{array}{r} &1.50\\ +\!\!\!\!\!\!&2.14 \\ \hline \end{array} \\ \ \ \ \ \ \ \ \ \ \ .64\). Add the ones place. \(2 \ + \ 1=3\), \(\begin{array}{r} &1.50\\ +\!\!\!\!\!\!&2.14 \\ \hline \end{array} \\ \ \ \ \ \ \ \ 3.64\)
Example 2:
Subtract decimals. \(2.56 \ – \ 1.15= \begin{array}{r} &2.56\\ – \!\!\!\!\!\!&1.15\\ \hline \end{array} \)
Solution:
Start with the hundredths place. \(6 \ – \ 5=1\), \(2.56 \ – \ 1.15= \begin{array}{r} &2.56\\ – \!\!\!\!\!\!&1.15\\ \hline \end{array} \) continue with tenths place. \(5 – 1=4\)
\(\begin{array}{r} &2.56\\ – \!\!\!\!\!\!&1.15 \\ \hline \end{array} \\ \ \ \ \ \ \ \ 0.41\), subtract the ones place. \(2-1=1\), \( \begin{array}{r} &2.56\\ – \!\!\!\!\!\!&1.15 \\ \hline \end{array} \\ \ \ \ \ \ \ \ 1.41\)
Example 3:
Add. \(2.5 \ + \ 1.24=\)
Solution:
First line up the numbers: \(\begin{array}{r} &2.5\\ +\!\!\!\!\!\!&1.24\\ \hline \end{array}→ \) Add zeros to have same number of digits for both numbers. \(\begin{array}{r} &2.50\\ +\!\!\!\!\!\!&1.24\\ \hline \end{array} \), Start with the hundredths place. \(0 \ + \ 4=4\), \(\begin{array}{r} &2.50\\ +\!\!\!\!\!\!&1.24 \\ \hline \end{array} \\ \ \ \ \ \ \ \ \ \ \ 4\), Continue with tenths place. \(5 \ + \ 2=7\), \(\begin{array}{r} &2.50\\ +\!\!\!\!\!\!&1.24 \\ \hline \end{array} \\ \ \ \ \ \ \ \ \ \ .74\) . Put the decimal point and add the ones place. \(2 \ + \ 1=3\), \(\begin{array}{r} &2.50\\ +\!\!\!\!\!\!&1.24 \\ \hline \end{array} \\ \ \ \ \ \ \ \ 3.74\)
Example 4:
Subtract decimals. \(4.67 \ – \ 2.15= \begin{array}{r} &4.67\\ – \!\!\!\!\!\!&2.15\\ \hline \end{array} \)
Solution:
Start with the hundredths place. \(7 \ – \ 5=2\), \( \begin{array}{r} &4.67\\ – \!\!\!\!\!\!&2.15\\ \hline \end{array} \\ \ \ \ \ \ \ \ 2 \), continue with tenths place. \(6 \ – \ 1=5\), \( \begin{array}{r} &4.67\\ – \!\!\!\!\!\!&2.15\\ \hline \end{array} \\ \ \ \ \ \ \ \ \ \ \ .52 \), put the decimal point and subtract the ones place. \(4 \ – \ 2 =2\), \( \begin{array}{r} &4.67\\ – \!\!\!\!\!\!&2.15\\ \hline \end{array} \\ \ \ \ \ \ 2.52 \)
Exercises
Add and subtract decimals.
\(\color{blue}{ \begin{array}{r} &15.14\\ -\!\!\!\!\!\!&12.18\\ \hline \end{array} }\)
\(\color{blue}{ \begin{array}{r} &65.72\\ +\!\!\!\!\!\!&43.67\\ \hline \end{array} }\)
\(\color{blue}{ \begin{array}{r} &82.56\\ +\!\!\!\!\!\!&12.28\\ \hline \end{array} }\)
\(\color{blue}{ \begin{array}{r} &34.18\\ -\!\!\!\!\!\!&23.45\\ \hline \end{array} }\)
\(\color{blue}{ \begin{array}{r} &90.37\\ +\!\!\!\!\!\!&56.97\\ \hline \end{array} }\)
\(\color{blue}{ \begin{array}{r} &45.78\\ -\!\!\!\!\!\!&23.39\\ \hline \end{array} }\)
Download Adding and Subtracting Decimals Wksheetor
Answers
- \(\color{blue}{2.96}\)
- \(\color{blue}{109.39}\)
- \(\color{blue}{94.84}\)
- \(\color{blue}{10.73}\)
- \(\color{blue}{147.34}\)
- \(\color{blue}{22.39}\)
