Fractions · Decimals & percents · 9.5

Forms mastery.

Fluency means switching between fraction, decimal, and percent without hesitation, and knowing the common ones (½ = 0.5 = 50%, ¼ = 0.25 = 25%).

01 / THE IDEA

See it work.

Watch the method

Forms mastery

2/5 = 0.4 = 40%.

1 / 1
25\frac{2}{5}
1

Out of 100

Percent means per hundred.

25=40100=40%\frac{2}{5} = \frac{40}{100} = 40\%
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.

Three forms, one number

Memorise the common equivalents and convert the rest by dividing or scaling to 100.

Why it works

Same number, three outfits.

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

Write as a percent 6/20

1

Out of 100

Percent means per hundred. 3/10 = 30/100 = 30\%

EX 2medium

Write as a percent 1/5

1

Out of 100

Percent means per hundred. 1/5 = 20/100 = 20\%

EX 3hard

Write as a percent 2/25

1

Out of 100

Percent means per hundred. 2/25 = 8/100 = 8\%

04 / COMMON TRAPS

Where students slip.

Trap

Re-deriving ½ = 50% every time.

Fix

Memorise the common ones.

Trap

Mixing up the conversion direction.

Fix

Fraction → decimal: divide; → percent: × 100.

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

Write as a percent 6/20

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
C2

Write as a percent 15/25

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
C3

Write as a percent 1/5

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
C4

Write as a percent 2/5

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
Apply

Apply (4)

A1

Write as a percent 1/5

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
A2

Write as a percent 7/10

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
A3

Write as a percent 1/50

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
A4

Write as a percent 1/2

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
Extension

Extension (4)

E1

Write as a percent 2/25

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
E2

Write as a percent 4/5

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
E3

Write as a percent 3/5

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.
E4

Write as a percent 11/20

Need a hint?
  • Recall the common equivalents.
  • Convert the rest by dividing or ×100.