Kathy is baking cakes. If each cake requires #1/12# of a teaspoon of vanilla, and she has #9/12# of a teaspoon, how many cakes can she bake?

1 Answer
Nov 3, 2016

She can bake #9# cakes.

Explanation:

Assuming she has enough of the other ingredients, the amount of vanilla is the limiting factor.

She can use it up #1/12# of a teaspoon at a time..

How many portions of #1/12# are there in #9/12#?

By observation and reasoning we can see it is #9#.

However, other questions might not be as obvious, so let's look at the math as well. We need to do a division operation...

#9/12 div 1/12" "larr# multiply by the reciprocal of #1/12#

#9/12 xx12/1 = 9# cakes

[note that in this case you can also just divide straight across because you get an exact answer for both]

#9/12 div 1/12 = (9div1)/(1div12) = 9/1 = 9# cakes