We are told that Benjamin has
9 cups of sugar, and that this amount is
$\frac{3}{4}$ of the total amount he *needs* to make the cake.
So, we’re being asked:
> If 9 cups = $\frac{3}{4}$ of the total needed, what is the
whole (i.e., 100% or $\frac{4}{4}$) amount?
---
Step-by-step Solution:
Let’s call the total amount of sugar Ben needs
$x$ cups.
According to the problem:
$$
\frac{3}{4} \cdot x = 9
$$
To solve for $x$, divide both sides by $\frac{3}{4}$:
$$
x = 9 \div \frac{3}{4}
$$
Remember: dividing by a fraction is the same as multiplying by its reciprocal.
$$
x = 9 \times \frac{4}{3}
$$
Now compute:
$$
9 \times \frac{4}{3} = \frac{9 \times 4}{3} = \frac{36}{3} = 12
$$
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Visual Explanation (using the bar model shown):
The bar is divided into 4 equal parts (since we’re dealing with quarters).
We’re told that 3 of those parts = 9 cups.
So, each part = $9 \div 3 = 3$ cups.
Therefore, the whole bar (4 parts) = $4 \times 3 = 12$ cups.
---
Final Answer:
✔ Ben needs 12 cups.
Fill in the blanks:
- $9 \div \frac{3}{4} = \boxed{12}$
- Ben needs $\boxed{12}$ cups.
Parent Tip: Review the logic above to help your child master the concept of dividing whole numbers by fractions word problems worksheet.