2.2: Multiplying and Dividing Decimals

Last updated
Save as PDF

Page ID: 7087

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

Multiplying and dividing decimals is simple enough if you use a calculator. When multiplying decimals, there is no certain order you need to type the numbers in your calculator.

Example \(\PageIndex{1}\)

0.255 × 0.23 = 0.05865

25 × 35 = 875

100.5 × 12.75 = 1,281.375

Exercise 2.2

Multiply the following problems

\(\begin{array}{r}
5 \\
\times 0.35\\ \hline
\end{array}\)
\(\begin{array}{r}
65 \\
\times 0.2\\ \hline
\end{array}\)
\(\begin{array}{l}
0.515 \\
\times 0.15\\ \hline
\end{array}\)
\(\begin{array}{l}
20.54 \\
\times 5.01\\ \hline
\end{array}\)
\(\begin{array}{l}
0.002 \\
\times 1.07\\ \hline
\end{array}\)
\(\begin{array}{r}
0.9 \\
\times 0.8\\ \hline
\end{array}\)
\(\begin{array}{r}
8.5 \\
\times 0.2\\ \hline
\end{array}\)
\(\begin{array}{r}
52 \\
\times 0.11\\ \hline
\end{array}\)
\(\begin{array}{r}
0.4 \\
\times 0.04\\ \hline
\end{array}\)
\(\begin{array}{r}
4.23 \\
\times 2\\ \hline
\end{array}\)
\(\begin{array}{r}
0.2 \\
\times 0.45\\ \hline
\end{array}\)
\(\begin{array}{r}
2.68 \\
\times 0.298\\ \hline
\end{array}\)

When dividing decimals, the denominator (or the divisor) is divided into the numerator (or the dividend). The resultant answer is termed the quotient. In the example below, 25 is divided into 125. On your calculator, you would type in the 125 first and then the 25. It is read as 125 divided by 25.

Example \(\PageIndex{2}\)

\(\begin{array}{ll}
\dfrac{125}{25}= & 5 \\
\dfrac{1.25}{25}= & 0.05 \\
\dfrac{1.25}{0.25}= & 5
\end{array}\)

Exercise 2.2.1

Divide the following problems.

\(0.6 \div 5=\)
\(28 \div 7=\)
\(14 \div 20=\)
\(0.54 \div 12=\)
\(75 \div 40=\)
\(1.44 \div 12=\)
\(0.48 \div 2.4=\)
\(156 \div 0.78=\)