Fractions · Multiply · 7.4

Fraction of a number.

“Of” means multiply. To find a fraction of a number, divide by the denominator and multiply by the numerator.

01 / THE IDEA

See it work.

Watch the method

Fraction of a number

½ of 12: 12 ÷ 2 = 6.

1 / 2
12 of 12\frac{1}{2} \text{ of } 12
1

Divide by the denominator

Split 12 into 2 equal parts.

12÷2=612 \div 2 = 6
2

Multiply by the numerator

Take 1 of those parts.

6×1=66 \times 1 = 6
02 / YOUR TURN

Practice until it feels automatic.

Your turn

Work it out.

Type a fraction like 3/4 or 1 1/2.

streak 0
best 0
… =
— / WHY IT WORKS

The idea underneath.

Of = multiply

n/d of N = N ÷ d × n. Find one part, then take n of them.

Why it works

Half of 12 is 6; two-thirds of 12 is 8.

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

What is 1/2 of 12

1

Divide by the denominator

Split 12 into 2 equal parts. 12 \div 2 = 6

2

Multiply by the numerator

Take 1 of those parts. 6 \times 1 = 6

EX 2medium

What is 1/2 of 12

1

Divide by the denominator

Split 12 into 2 equal parts. 12 \div 2 = 6

2

Multiply by the numerator

Take 1 of those parts. 6 \times 1 = 6

EX 3hard

What is 1/2 of 10

1

Divide by the denominator

Split 10 into 2 equal parts. 10 \div 2 = 5

2

Multiply by the numerator

Take 1 of those parts. 5 \times 1 = 5

04 / COMMON TRAPS

Where students slip.

Trap

Multiplying by the denominator.

Fix

Divide by the denominator, multiply by the numerator.

Trap

Thinking “of” means add.

Fix

“Of” means multiply.

05 / QUIZ

Test yourself.

The Test

12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.

0/12Answered
How to answerType just the value. Formatting won't trip you up — we ignore spaces, capital letters, commas, and subscript style, so t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).
Core

Core (4)

C1

What is 1/2 of 12

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
C2

What is 1/3 of 12

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
C3

What is 1/2 of 12

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
C4

What is 3/5 of 10

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
Apply

Apply (4)

A1

What is 1/2 of 12

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
A2

What is 2/5 of 10

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
A3

What is 3/5 of 25

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
A4

What is 1/4 of 8

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
Extension

Extension (4)

E1

What is 1/2 of 10

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
E2

What is 3/5 of 20

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
E3

What is 1/2 of 12

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.
E4

What is 2/5 of 40

Need a hint?
  • Divide by the bottom.
  • Multiply by the top.