Basic proportion question I’m struggling with please help math wiz!

[Sy92]

Hi guys,

Im struggling to understand which goes first when it comes to division for a proportion question. I keep getting it mixed and getting the wrong answer. For example 15 almonds weigh 9g, what is the weight of 1 almond per gram. I can see it’s 9/15. Or if it’s how much almonds there are per gram 15/9. But I keep struggling with the order of the division with these question types. Can someone offer me advice/trick so I can figure out what number to divide first?

Embarrassingly bad at math,

Sy

 

[Dr.Peterson]

Just keep the units with the numbers until everything is set up. If you want the weight (in grams) of one almond, that isn't "per gram"; it's "grams per almond". So it has to be 9g/15 almonds = 9/15 g/almond. If you want the number of almonds in a gram, that's "almonds per gram", so you use 15 almonds/9 g = 15/9 almonds/g.

I suspect you have trouble in a harder type of problem that you haven't shown us. Can you give an example of something you aren't sure of, and show an attempt? Then we'll see better what you are missing.

 

[Steven G]

As Dr Peterson said, the units of each fraction must match. Never have gms/almonds = almonds/gms