What is a Reciprocal?

What is a Reciprocal?

The reciprocal of a number is called a multiplicative inverse.  The product of a number and its reciprocal is 1.

To find the reciprocal of a whole number you must first put it over 1.  

•  $5\ =\ \frac{5}{1}\ the\ reciprocal\ is\ \frac{1}{5}$  

•  $28\ =\ \frac{28}{1}\ the\ reciprocaql\ is\ \frac{1}{28}$  

Multiple Choice

What is the reciprocal of 4?

•  $\frac{4}{1}$  

•  $\frac{1}{4}$  

Multiple Choice

What is the reciprocal of 83?

• $\frac{1}{83}$

• $\frac{83}{1}$

To find the reciprocal of a fraction you just flip it upside down.

• the numerator becomes the denominator

• the denominator becomes the numerator.

•  $\frac{2}{3\ }\ \rightarrow\ \frac{3}{2}$  

Multiple Choice

The reciprocal of

 $\frac{5}{7}$  is

•  $\frac{5}{7}$  

•  $1\ \frac{2}{7}$  

•  $\frac{7}{5}$  

Multiple Choice

The reciprocal of $\frac{21}{33}$   is

•  $\frac{21}{33}$  

•  $\frac{33}{21}$  

•  $1\ \frac{12}{33}$  

To find the reciprocal of a mixed number

• turn the mixed number into an improper fraction

• flip the fraction over

•  $2\ \frac{3}{4}\ =\ \frac{11}{4}\ \ \rightarrow\ \ \frac{4}{11}$  

Multiple Choice

 $1\frac{4}{7}\ as\ an\ improper\ fraction\ is$  

•  $\frac{7}{11}$  

•  $\frac{11}{7}$  

•  $\frac{12}{7}$  

Multiple Choice

 $The\ rciprocal\ of\ 1\ \frac{4}{7}\ is$  

•  $\frac{11}{7}$  

•  $\frac{7}{11}$  

Multiple Choice

 $The\ reciprocal\ of\ 8\ \frac{1}{2}\ is$  

•  $\frac{17}{2}$  

•  $\frac{2}{17}$  

•  $\frac{11}{2}$  

Poll

I can find the reciprocal of a number

• Yes!

• No

• I'm still confused