Multiplying and Dividing Rational Numbers

Multiplying and Dividing Rational Numbers

​Remember:

​Rational numbers are numbers that can be written as a fraction, decimal that ends, or decimal that repeats.

• -​8

• ​4.213

• ​7.23232323....

• ​

Multiple Choice

Choose the number that is NOT rational

• $$5.7$$  

• $$0.\overline{3}$$  

• $$3.28390...$$  

• $$\frac{4}{5}$$  

​Multiplying

• ​Combine the rules you know for integers and how to multiply fractions and decimals.

• ​Examples:

Multiple Choice

Multiply. Make sure your final answer is in simplest form.

$$-\frac{7}{9}\times\frac{9}{8}=$$  

• $$-\frac{7}{8}$$  

• $$-\frac{54}{70}$$  

• $$\frac{7}{8}$$  

• $$\frac{54}{70}$$  

Multiple Choice

Alex made a rectangular quilt that measured $$3\ \frac{1}{4}$$  feet in length by $$2\ \frac{3}{4}$$  feet in width. What is the area?

Hint: Multiply the length and width.

• $$8\ \frac{15}{16}$$  

• $$6\ \frac{3}{4}$$  

• $$8\ \frac{5}{6}$$  

• $$9\ \frac{1}{4}$$  

Multiple Choice

$$\left(-4.25\right)\times\left(-3.1\right)=$$  

• $$1.3175$$  

• $$-13.175$$  

• $$13.175$$  

• $$-131.75$$  

​Dividing Rational Numbers

• ​Follow the steps you know for dividing fractions (Keep, Change, Flip) and decimals.

• ​Use what you know about dividing integers to figure out the sign of your answer.

• ​Examples:

Multiple Choice

$$5.75\div\left(-0.25\right)=$$  

• $$23$$  

• $$-2.3$$  

• $$2.03$$  

• $$-23$$  

Multiple Choice

$$3\ \frac{1}{2}\div-2\ \frac{1}{6}=$$  

• $$-6\ \frac{1}{3}$$  

• $$-1\ \frac{8}{13}$$  

• $$6\ \frac{1}{3}$$  

• $$\frac{42}{26}$$  

Multiple Choice

$$-\frac{1}{5}\div-\frac{2}{5}=$$  

• $$-\frac{1}{2}$$  

• $$\frac{1}{5}$$  

• $$\frac{1}{2}$$  

• $$-\frac{1}{5}$$