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Grade 4 Math · Level 6, Grade 5 Preview

Bridge: Unlike-Denominator Fraction Addition

How the lesson starts: Bridge: Unlike-Denominator Fraction Addition

1. The giggle potion

   Hello, young wizard! Wizard Milo is mixing a giggle potion. He pours in 1/2 cup of berry juice and 1/4 cup of fizzy water. How much potion is in the pot? The pieces are different sizes, so we need a magic trick!

2. Rename the half

   Halves and fourths are different sizes, so we can't just add 1 + 1. Milo cuts each half into 2 equal pieces. Now the half shows 2 fourths! 1/2 = 2/4. Then 2/4 + 1/4 = 3/4. Never add the bottoms!

3. Subtract the same way

   Milo has 3/4 cup of moon milk. He uses 1/2 cup in a sneezing spell. How much is left? Rename 1/2 as 2/4. Now 3/4 − 2/4 = 1/4. Just 1/4 cup of moon milk is left!