# 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?

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 $\frac{1}{12}$ of a teaspoon at a time..

How many portions of $\frac{1}{12}$ are there in $\frac{9}{12}$?

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...

$\frac{9}{12} \div \frac{1}{12} \text{ } \leftarrow$ multiply by the reciprocal of $\frac{1}{12}$

$\frac{9}{12} \times \frac{12}{1} = 9$ cakes

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

$\frac{9}{12} \div \frac{1}{12} = \frac{9 \div 1}{1 \div 12} = \frac{9}{1} = 9$ cakes