1.2 “I can find equivalent fractions by multiplying or dividing the numerator and denominator by the same number.” 1.10 “I can explain why fractions need common denominators to be added or subtracted.” 1.12 “I can use manipulatives, points of reference and equivalent forms add and subtract commonly used fractions with like and unlike denominators.”

Why do you need to know this? Cooking Measuring Have you ever used a Ruler? 1/2 of a dollar Shopping Where do you see fractions?

Equivalent Fractions Equivalent - representing the _______ number or amounts. Denominator - the number ________ the bar in a fraction. Numerator - The number ________ the bar in a fraction. Common - Belonging equally to or shared equally by two or more.

How to find Equal Fractions? Multiply the numerator and denominator by the same number (Multiplying by 2/2 or 1) 1 x 2 = ___ 4 x 2

Simplifying Fractions Simplify - __________ the numerator and denominator by the same number. Find the GREATEST COMMON FACTOR (GCF) and divide. Factors: 3 / __ = __ 3: 3 x 1 9 / 9: 9 x 1, 3 x 3

Simplify 6/8 Factors: Find a fraction Equivalent to 2/3? A. 3/6 B. 4/5 C. 1/6 D. 4/6

Why do fractions need common denominators to be added or subtracted? The denominators have to be the same because the number of the parts when added or subtracted have to be the same size. Does it make sense to add slices of pizza together that are different sizes?

Adding and Subtracting Fractions with unlike Denominators. Must find a __________ denominator before adding or subtracting numerators. Find the Least Common Denominator (LCD) by finding the Least Common Multiple (LCM) 1 + 1 = LCM: 4: 4, 8, 12, 16 4 3 3: 3, 6, 9, 12, 15

Unlike Denominators 1 + 1 = LCM: 4: 4, 8, 12, 16 4 3 3: 3, 6, 9, 12, 15 Find Equivalent Fractions with the Least Common Denominator: Once the denominators are the same add or subtract the numerators and slide the denominator over. (Do not add or subtract the denominator)

Practice (CPS) Adding with Unlike Denominators Subtracting with Unlike Denominators 3 / 4 + 1 / 8 = 4/8 B. 2/8 C. 7/8 4 / 5 + 3 / 10 = A. 11/10 B. 7/10 C. 7/15

What did you learn today? List: