Week 1 Math Review Multiplying and Dividing Fractions

Multiplying Fractions

Multiplying Fractions

• 3/5

• In the fraction above, the top number is called the numerator

• The bottom number is called the denominator

• These are important terms to remember because you will hear them a lot when multiplying and dividing fractions.

Multiplying Fractions

• The first step in multiplying fractions is to multiply the two numerators

• For example, you would multiply 2x2 to get 4 as your new numerator

• Next, you multiply both denominators, 3x5, to get 15 as your new denominator

• Your new fraction should now be 4/15

Multiple Choice

What is the first step when you multiply fractions?

• Multiply the denominators

• Multiply the numerators

• Neither

Multiple Choice

What is the second step when you multiply fractions/

• Multiply the numerators

• Multiply the denominators

• Neither

Let's try practicing simplifying fractions again

Simplifying your answer

Multiple Choice

What is the fraction 2/4 in simplest form?

• 1/2

• 1/4

• 2/2

• It is in simplest form

Poll

Does this make sense so far?

• Yes

• No

• Sort of

2/4 in simplest form is 1/2

Multiple Choice

$$\frac{1}{8}\times\frac{3}{4}$$  

• $$\frac{3}{32}$$  

• $$\frac{3}{30}$$  

• $$\frac{4}{12}$$  

• $$\frac{3}{15}$$  

Multiple Choice

$$\frac{2}{3}\times\frac{3}{4}$$  

• $$\frac{1}{2}$$  

• $$\frac{6}{7}$$  

• $$\frac{5}{8}$$  

• $$\frac{3}{15}$$  

Multiple Choice

$$\frac{1}{3}\times\frac{2}{5}$$  

• $$\frac{2}{15}$$  

• $$\frac{3}{8}$$  

• $$\frac{2}{8}$$  

• $$\frac{3}{15}$$  

Multiple Choice

Solve. Make sure answer is in simplest form.

• $$\frac{5}{8}$$

• $$\frac{8}{10}$$

• $$\frac{15}{8}$$

• $$\frac{8}{24}$$

Dividing Fractions

What do you know?

Remember: The rules to divide fractions are Keep Change Flip

Recuerde: las reglas para dividir fracciones son Keep Change Flip

Multiple Choice

What does reciprocal mean?

• Stay the same

• Flip

Multiple Choice

What is the reciprocal of:

$$\frac{2}{5}$$  

• $$\frac{2}{5}$$  

• $$\frac{5}{2}$$  

Multiple Choice

What is the reciprocal of:

$$\frac{5}{7}$$  

• $$\frac{7}{5}$$  

• 7

• $$\frac{5}{7}$$  

Multiple Choice

What is the reciprocal of: 2

• $$\frac{2}{1}$$  

• 2

• $$\frac{1}{2}$$  

Multiple Choice

What would this division sentence look like if you were solving it?

$$\frac{2}{3}\div\frac{4}{5}$$  

• $$\frac{2}{3}\times\frac{4}{5}$$  

• $$\frac{3}{2}\times\frac{4}{5}$$  

• $$\frac{2}{3}\times\frac{5}{4}$$  

Multiple Choice

What would this division sentence look like if you were solving it?

$$4\div\frac{2}{5}$$  

• $$\frac{4}{1}\times\frac{2}{5}$$  

• $$\frac{4}{1}\times\frac{5}{2}$$  

• $$\frac{1}{4}\times\frac{2}{5}$$  

Multiple Choice

Solve:

$$\frac{1}{2}\div\frac{3}{4}$$  

• $$\frac{3}{8}$$  

• $$\frac{4}{6}=\frac{2}{3}$$  

• $$\frac{6}{4}=\frac{3}{2}=1\ \frac{1}{2}$$  

Poll

How well do you understand this information?

• Not well at all

• A little

• I'm pretty good

• I understand!

Multiple Choice

• $$\frac{6}{40}$$

• $$\frac{3}{4}$$

• $$\frac{1}{2}$$

• $$\frac{12}{20}$$

Multiple Choice

Solve.

• $$\frac{8}{9}$$

• $$\frac{1}{5}$$

• 1

• $$\frac{4}{5}$$

Multiple Choice

What is the rule for Dividing Fractions?

• "Keep, Keep, Flip"

• "Keep, Change, Flip"

• "Keep, Change, Keep

• I don't know!

Multiple Choice

What is another word for "Flip"?

• Same

• Fraction

• Equal

• Reciprocal

Multiple Choice

How do you divide fractions?

• Use "KCF" and divide

• Just divide the numerators then the denominators

• Multiply the fractions

• Use "KCF" then multiply the numerators and denominators

Great job guys! Please use the rest of your time to do the practice problems on the worksheet!