courses › Fractions, Decimals & Percents

Totals, change, discounts, and changes on top of changes.

In your head, jot if needed · no calculator why?

Learn first (about 3 minutes)

Opens at level 13.

Sign in to start

Builds on: Decimals (not open yet) · Percents (not open yet)

skills · practice stats

From rounds of this course only: box, review and trial answers are left out. Once a skill has 40 tries, it compares your first 20 tries with your last 20.

• Money totals par 7 s not tried yet

  worked example

  $40.20 + $55.50 + $12.90

  Answer: $108.60

  1. The cents make $1.60: 20¢ + 50¢ + 90¢ = 160¢.
  2. Dollars first, then cents: $107 + $1.60 = $108.60.

• Making change par 9 s not tried yet

  worked example

  You pay $20 for a $13.25 item. How much change do you get?

  Answer: $6.75

  1. Count up: $13.25 → $14 is 75¢, and $14 → $20 is $6.
  2. Change: $6.75.

• Final price par 10 s not tried yet

  worked example

  What is the final price after 20% off $362?

  Answer: $289.60

  1. 20% of $362 is $72.40.
  2. $362 − $72.40 = $289.60.

• Change after change par 13 s not tried yet

  worked example

  Increase 100 by 20%, then decrease the result by 25%. What is the final amount?

  Answer: 90

  1. 100 × 1.2 = 120, then 120 × 0.75 = 90.
  2. The second percent is taken of the new amount, 120, not of 100.

rest ladder

Win 3 of your last 4 rounds and the course rests. A win is 90% right, within 2× the round's par. Pass the review when it comes back and the next rest is longer.

1. 1 day
2. 3 days
3. 7 days
4. 14 days
5. 30 days
6. 60 days
7. mastered · every 90 days

your rounds

No rounds yet.