Skill: Divide a unit fraction by a whole number

To divide a unit fraction by a whole number, split the unit fraction into that many equal parts.

For a unit fraction $\frac{1}{b}$ divided by $n$:

$$\frac{1}{b}\div n=\frac{1}{b\cdot n}$$

Example: Find $\frac{1}{4}\div 3$.

1. Think of $\frac{1}{4}$ as one of four equal parts of a whole.
2. Split that $\frac{1}{4}$ part into $3$ equal pieces.
3. The whole is now divided into $4\cdot 3=12$ equal pieces, so each small piece is $\frac{1}{12}$.

Therefore,

$$\frac{1}{4}\div 3=\frac{1}{4\cdot 3}=\frac{1}{12}$$

You can check by multiplying the answer by $3$:

$$3\cdot\frac{1}{12}=\frac{3}{12}=\frac{1}{4}$$

So, $\frac{1}{12}$ is the correct answer.