says I should “change” my shirt before she “flips” her lid! Dividing Fractions Made Easy! Using… keep My momma says I should “change” my shirt before she “flips” her lid! Change! Flip! CCSS 5NBT.B.7 © Mike’s Math Mall

doesn’t remember what he had for breakfast! Dividing Fractions Because with a little change to a division of fractions’ problem, you’ll be right back to multiplying! Dividing fractions sounds hard, but if you remember how to multiply fractions, then you’re in luck! Sparky doesn’t remember what he had for breakfast! We better review!

Multiplying Fractions Review To multiply fractions, we multiply numerator by numerator and denominator by denominator. 𝟐 𝟑 × 𝟑 𝟒 = 𝟔 𝟏𝟐 ÷𝟔 ÷𝟔 = 𝟏 𝟐 Or you can “cross-cancel” to simplify: Don’t forget to simplify! 𝟐 𝟑 × 𝟑 𝟒 1 = 𝟏 𝟐 1 1 2

Multiplying Fractions Review And that cross-cancelling thing is sweet! Can we do another one… pleeeease? Now I remember how to multiply fractions! Awesome! Absolutely! But let’s look at how to divide fractions first!

Dividing Fractions By using the phrase, “keep, change, flip,” we can easily turn a division of fractions’ problem into a multiplication problem. Dividing fractions is a tricky concept. It’s actually easier to multiply them. “Keep, change, flip” means multiply by the reciprocal in the big leagues. 3 ft 1 in I’m a big leaguer! Yeah, we can tell! (wink-wink)

Remember! Think “keep, change, flip”! Dividing Fractions 𝟐 𝟑 ÷ 𝟑 𝟒 Let’s try one! 𝟐 𝟑 Keep– Keep the first fraction Remember! Think “keep, change, flip”! 𝟐 𝟑 × Change – Change the division symbol to multiplication: Flip – Flip (invert) the second fraction: 𝟐 𝟑 × 𝟒 𝟑

And just like that, we’re back Dividing Fractions And just like that, we’re back to multiplying! 𝟐 𝟑 ÷ 𝟑 𝟒 = 𝟖 𝟗 𝟐 𝟑 × 𝟒 𝟑 = Since 𝟖 𝟗 is simplified, we’re done! That “keep, change, flip” thing is kinda cool, but I’m not quite sure I have it. Then let’s do another one!

Dividing Fractions 𝟒 𝟗 ÷ 𝟖 𝟏𝟓 𝟒 𝟗 𝟒 𝟗 × 𝟒 𝟗 𝟏𝟓 𝟖 × Keep: Change: Flip: Give this a try! 𝟒 𝟗 Keep: Change: 𝟒 𝟗 × Flip: 𝟒 𝟗 × 𝟏𝟓 𝟖

Or we could cross-cancel! Dividing Fractions 𝟒 𝟗 × 𝟏𝟓 𝟖 = 𝟔𝟎 𝟕𝟐 𝟒 𝟗 ÷ 𝟖 𝟏𝟓 = Simplify! 𝟔𝟎÷𝟐 𝟕𝟐÷𝟐 = 𝟑𝟎÷𝟔 𝟑𝟔÷𝟔 = 𝟓 𝟔 Or we could cross-cancel! I tried to simplify my sister once. Momma cross-cancelled that plan! 𝟒 𝟗 × 𝟏𝟓 𝟖 = 𝟓 𝟔 1 5 3 2 Ouch! Oh, yeah? How’d that end up?

Show Your Stuff! Divide the following fractions. Simplify answers when necessary. 𝟒 𝟓 1) 𝟏 𝟐 ÷ 𝟐 𝟑 = 𝟑 𝟒 2) 𝟑 𝟓 ÷ 𝟑 𝟒 = 𝟐 𝟑 𝟖 𝟏𝟓 3) 𝟐 𝟔 ÷ 𝟏 𝟐 = 4) 𝟏 𝟑 ÷ 𝟓 𝟖 = 𝟏 𝟐 𝟒 𝟓 5) 𝟒 𝟗 ÷ 𝟖 𝟗 = 6) 𝟕 𝟏𝟎 ÷ 𝟏𝟒 𝟏𝟔 =

Dividing Fractions How’d you do on the practice problems, Sparky? Why? Do you have big plans later? I did great! But what about dividing fractions with whole numbers? Ok! But will this take long? Four words… Burrito Factory… free samples. That’s actually a great question! We better take a look at that. We’ll hurry!

First, we need to change the 3 into a fraction by placing it over 1. Dividing Fractions 𝟓 𝟖 ÷ ÷ 𝟑 𝟏 Take a look at this one! 𝟑 First, we need to change the 3 into a fraction by placing it over 1. 𝟓 𝟖 Now we’re ready for keep, change, flip! Keep: 𝟓 𝟖 × Change: 𝟓 𝟖 × 𝟏 𝟑 = 𝟓 𝟐𝟒 Flip:

Here’s another example: A few more peppery practice problems! Dividing Fractions Here’s another example: 𝟒 𝟏 ÷ ÷ 𝟐 𝟕 𝟒 𝟒 𝟏 ÷ 𝟐 𝟕 = 𝟒 𝟏 × 𝟕 𝟐 Create a fraction! = 𝟏𝟒 𝟏 2 =14 1 Some free, spicy, beefy burrito samples! Do you smell that? Hey, that wasn’t so bad! Very funny! What? A few more peppery practice problems! No, but do you smell that? I never said it would be! Smell what?

Show Your Stuff! Divide the following fractions. Simplify answers when necessary. 1) 𝟒 𝟓 ÷4= 𝟏 𝟓 2) 6÷ 𝟑 𝟒 = 8 Extension) 1 𝟑 𝟒 ÷2 𝟓 𝟖 = 𝟕 𝟒 ÷ 𝟐𝟏 𝟖 = 2 𝟐 𝟑 1 𝟕 𝟒 × 𝟖 𝟐𝟏 = 1 3

And how’s that working out? Dividing Fractions Remember, Sparky! You can only cross-cancel after a division of fractions’ problem has been changed to multiplication. I’m always trying to remember to not hold in my sneezes. Have you seen the size of my head? And how’s that working out? Point taken! © Mike’s Math Mall

Dividing Mixed Numbers You must first change the mixed number into an improper fraction. Ex. 6 𝟏 𝟐 ÷ 4 2 3 13 2 ÷ 14 3 = Once you have converted from a mixed number, you must KEEP, CHANGE, FLIP. 13 2 ÷ 14 3 13 2 × 3 14 = 39 28 = 1 11 28 ***Don’t forget to convert back to a mixed number and simplify if necessary. Keep, Change, Flip

Show Your Stuff! Divide the following fractions. Simplify answers when necessary.