Adding and Subtracting Decimals

Learn how to add and subtract decimals in a few simple steps.

Step by step guide to add and subtract decimals

1. Line up the numbers.
2. Add zeros to have the same number of digits for both numbers if necessary.
3. 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.

1. \(\color{blue}{ \begin{array}{r} &15.14\\ -\!\!\!\!\!\!&12.18\\ \hline \end{array} }\)

2. \(\color{blue}{ \begin{array}{r} &65.72\\ +\!\!\!\!\!\!&43.67\\ \hline \end{array} }\)

3. \(\color{blue}{ \begin{array}{r} &82.56\\ +\!\!\!\!\!\!&12.28\\ \hline \end{array} }\)

4.\(\color{blue}{ \begin{array}{r} &34.18\\ -\!\!\!\!\!\!&23.45\\ \hline \end{array} }\)

5. \(\color{blue}{ \begin{array}{r} &90.37\\ +\!\!\!\!\!\!&56.97\\ \hline \end{array} }\)

6. \(\color{blue}{ \begin{array}{r} &45.78\\ -\!\!\!\!\!\!&23.39\\ \hline \end{array} }\)

Download Adding and Subtracting Decimals Wksheetor

1. \(\color{blue}{2.96}\)
2. \(\color{blue}{109.39}\)
3. \(\color{blue}{94.84}\)
4. \(\color{blue}{10.73}\)
5. \(\color{blue}{147.34}\)
6. \(\color{blue}{22.39}\)