Lesson 3.3.1 Dividing Fraction and Mixed Numbers
Recap of what we have learned in chapters 2 and 3.
Modeled addition and subtraction on a number line with the Storm Chasers and Henry the hiker.
Added and subtracted integers, fractions, and decimals using rules. Christ of the Abyss -15 + (-7)
Multiplied integers, fractions, and decimals using rules. 3 1 2 • body Weight Super Gravity!
The only thing left is… Division!
Today… We will review what you have learned in previous grades about dividing fractions. Section 1: Vocabulary Section 2: Strategy for dividing fractions and mixed numbers Section 3: Guided and independent practice
Let’s get started… Section 1: Vocabulary Reciprocals – Two numbers are reciprocals if their product = 1. To get the reciprocal of a fraction, just flip it over. The reciprocal of 𝟑 𝟒 is………… 𝟒 𝟑 𝟑 𝟒 x 𝟒 𝟑 = 𝟏𝟐 𝟏𝟐 = 1 What is the reciprocal of 𝟓 𝟖 ? ________ The reciprocal of 5/8 is 8/5
Moving on… We will review what you have learned in previous grades about dividing fractions. Section 1: Vocabulary Section 2: Strategy for dividing fractions and mixed numbers Section 3: Guided and independent practice
K C F Strategy Keep It! Change It! Flip It! Section 2: Strategy for Dividing Fractions and Mixed Numbers K C F Keep It! Change It! Flip It! I have a strategy that will help us remember how to divide fractions. It’s called KCF. Keep it! Change it! Flip it! Let’s take a look using a real-world example.
Dividing Fractions 12 ÷ 1 𝟏 𝟑
Convert Convert any mixed number to improper fractions. 12 ÷ 1 𝟏 𝟑 12 ÷ 𝟒 𝟑
Keep it Change it Flip it Apply Strategy Keep it Change it Flip it 12 1 ÷ 4 3 Discuss how to set up the problem using the KCF strategy. 12 1 3 4 ×
Multiply 12 1 × 3 4 = = 𝟗 9 1 Now multiply to find your answer! 3 1 12 1 × 3 4 9 1 = = 𝟗 1 You may need to review how to cross cancel.
Dividing Fractions 9 mph 12 ÷ 1 𝟏 𝟑
Another Example
Common Denominator Method Step 1: Convert any mixed Numbers to Improper Fractions 3 ÷ 13 2 4 There are no improper fractions Step 2: Find the common denominator & re-write the equivalent fraction 6 ÷ 13 4 4 Step 3: Cross out the denominators and divide the numerators only (left to right) Write as a fraction 6 ÷ 13 4 4 6_ 13
Last section… We will review what you have learned in previous grades about dividing fractions. Section 1: Vocabulary Section 2: Strategy for dividing fractions and mixed numbers Section 3: Guided and independent practice
Practice Section 3: Guided and independent practice Check student notes answer keys for answers.
Practice Check student notes answer keys for answers.
Closure 𝟓 𝟔 ÷ 𝟒 𝟓 = What is our strategy for dividing fractions? 2) What is the reciprocal of 𝟐 𝟑 ? 3) How would you change the following division problem to a multiplication problem? 𝟏 𝟐 ÷ 𝟐 𝟑 = 𝟓 𝟔 ÷ 𝟒 𝟓 = 4) What MUST you do to all mixed numbers when multiplying and dividing? Keep it, Change it, Flip it (KCF) 𝟑 𝟐 𝟏 𝟐 × 𝟑 𝟐 𝟓 𝟔 × 𝟓 𝟒 Turn them to improper fractions!
Exit Ticket
Exit Ticket 18/4; 4 1/2 –2 𝟏 𝟐 –1 𝟏 𝟑 5 𝟏 𝟑
Time for Classwork!
End of PowerPoint