Multiplying and Dividing Fractions Year 7
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Multiplying and Dividing Fractions
Year 7 Mathematics Building Fraction Skills Real-Life Applications
What Are Fractions?
A fraction represents part of a whole The top number is the numerator (parts we have) The bottom number is the denominator (total parts) Examples: 1/2, 3/4, 5/8
Multiplying Fractions - The Rule
Multiply the numerators together Multiply the denominators together Simplify the result if possible Formula: a/b × c/d = (a×c)/(b×d)
Practice: Multiplying Fractions
Work out: 2/3 × 1/4 Step 1: Multiply numerators: 2 × 1 = 2 Step 2: Multiply denominators: 3 × 4 = 12 Answer: 2/12 = 1/6 (simplified)
Real-Life Example: Cooking
Recipe calls for 3/4 cup of flour You want to make half the recipe Calculate: 1/2 × 3/4 Answer: 3/8 cup of flour needed
Dividing Fractions - The Rule
To divide fractions, multiply by the reciprocal Reciprocal means 'flip' the second fraction Then multiply as normal Formula: a/b ÷ c/d = a/b × d/c
Practice: Dividing Fractions
Work out: 3/4 ÷ 1/2 Step 1: Keep the first fraction: 3/4 Step 2: Change ÷ to × Step 3: Flip the second fraction: 1/2 becomes 2/1 Step 4: Multiply: 3/4 × 2/1 = 6/4 = 1 1/2
Real-Life Example: Construction
A board is 7/8 meter long Need to cut it into pieces 1/4 meter each How many pieces? 7/8 ÷ 1/4 7/8 × 4/1 = 28/8 = 3 1/2 pieces
Challenge Problem
A recipe needs 2/3 cup of sugar You want to make 1 1/2 times the recipe How much sugar do you need? Think: 2/3 × 1 1/2 = ?
Key Takeaways
Multiplying fractions: multiply numerators and denominators Dividing fractions: keep, change, flip, then multiply Always simplify your final answer Fractions are everywhere in real life! Practice makes perfect