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### Unit 2: Lesson 3

Lesson 3: Recipes

# Equivalent ratios: recipe

Sal uses a recipe to explore equivalent ratios.

## Want to join the conversation?

• What if you have a number of guests like 20 guests coming over for your dinner party?
• You would, find 32 divided by 20 (which equals 1.6) and you would divide all the ingredients by 1.6
• when will we use ratios in real life, other than baking?
• like comparing prices per ounce while grocery shopping, calculating the proper amounts for ingredients in recipes and determining how long car trip might take.
• Thank you so much Sal! I learnt alot about ratios, I just have 1 question, can you teach us how to make them equal like if there were, lik, 19 people coming over?
• If you have 32 as the starting point, 1/2 and 1/4 are very natural ratios, but if you have 19 people, this a very awkward ratio of 19/32, so multiplying 19/32*8 = 4.75 makes it difficult to make a super cake with 3/4 of an egg. Or 10/32*6 = 3.5635 cups of flour. So if you have 19 guests, most people would tend to make the super cake that serves 32 and just expect to have leftovers.
Or they may say well what if I want to use 6 eggs which is 6/8 or 3/4 of each of the ingredients (3/4*32 = 24 people). 6*3/4 = 4 1/2 cups of flour and sugar or 2*3/4 = 6/4 or 1 1/2 cups of butter, etc.
• Does ratios work by what comes first like: 7 beach balls and 4 sand buckets, so would that mean the ratio is 7:4?
• yeah. it does depend on what comes first. if i was asked what the ratio of beach balls to sand buckets was, i could write "7:4" or "7 to 4"
• my teacher told me that order does not matter? How come?
• The order really does matter because if you have a problem like "For every 1 doughnut there is 3 cakes" your ratio can be 1:3, 2:6, 3:9. But if you notice the ratios I made was how many doughnuts there are first THEN how many cakes there are. Your teacher was probably confused or you were confused
• If you only have 16 people coming over then you should do half of the ingredients for the super cake!
• i dont really get some of these basic ratios but i know like 4:9 and stuff but like there saying your supooseto divide them
• I know i'm 2 years late but you can multiply and divide ratios. For example, the ratio 8:4. If you want to
multiply them by 4, you multiply each number by 4. So you get . If you want to simply them, divide them by 4. So it's 2:1. Hope this helps for those who don't get it.