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An equation which shows two equivalent ratios They help us to find relationships in the real world which are similar Method 1 -- Scale Factor Method 2 -- Cross Products Step 1 – Setup the Problem Julian is the best cake baker in Richmond. To make a cake, he uses 1 egg for every 2 cups of flour. If the recipe calls for 10 cups of flour, how many eggs does he need? Item Ratio eggs 1 X flour 2 10 Step 2 – Find number (scale factor) that you can multiply by to get from side with two numbers to side with variable. eggs 1 X flour 2 10 Step 2 – Find number (scale factor) that you can multiply by to get from side with two numbers to side with variable. x5 eggs 1 X flour 2 10 x5 Step 3 – Multiple to find the answer x5 eggs 1 X flour 2 10 x5 2 x 5 = 10 and 1 x 5 = 5; therefore, X = 5 Step 1 – Setup the Problem Tom is driving to New York. He travels 70 miles every 2 hours. If the trip takes 8 hours, how many miles will he travel? Ratio Miles 70 X Hours 2 8 Step 2 – Multiple numbers from top left to bottom right Miles 70 X Hours 2 8 70 8 = 560 Step 3 - Multiply numbers from top right to bottom left Miles 70 X Hours 2 8 2 · x = 2x Step 4 - Write products as an equation Miles 70 X Hours 2 8 560=2x Step 5 – Divide by this number to get x by itself 560=2x Wendy works at a kennel. There are 3 cats for every 2 dogs. If she takes in 18 cats, how many dogs will she have? Ratio Cats Dogs Simone is taking a trip to Florida for spring break. Her family travels 1250 miles in 25 hours. At their rate of travel, how many miles did they travel per hour? miles hours