Fractions help
Mixed numbers
A mixed number has a whole part and a fraction part — like 2 and 3/4. Adding and taking away mixed numbers is the same as adding ordinary fractions, with one extra thing to handle: the whole number part.
What this looks like in the game
You tap a fish and see something like "Work out 1 and 2/3 + 2 and 3/4." You drag tiles to build the answer — a mixed number, fully simplified.
Two ways to do it
Method 1 — Deal with the whole numbers and fractions separately
Add the whole numbers together. Add the fractions together. If the fraction part is bigger than 1, carry it into the whole number.
Method 2 — Convert to improper fractions first
Turn both mixed numbers into fractions where the top number is bigger than the bottom. Add them. Convert back. Method 2 is safer when taking away, because borrowing from the whole number can get confusing.
Worked example 1 — adding (same bottom numbers)
Whole numbers
1 + 2 = 3
Fractions
1/4 + 1/4 = 2/4 = 1/2
Answer: 3 and 1/2
Worked example 2 — subtracting (different bottom numbers)
Using method 2 — convert to improper fractions first.
Convert 3 and 1/2
(3 × 2) + 1 = 7 → 7/2
Convert 1 and 2/3
(1 × 3) + 2 = 5 → 5/3
Common bottom number: 2 × 3 = 6
7/2 = 21/6 · 5/3 = 10/6
21/6 − 10/6 = 11/6
Convert back: 11 ÷ 6 = 1 remainder 5
Answer: 1 and 5/6
The most common mistake
Watch out for
Converting a mixed number to an improper fraction incorrectly.
Wrong
3 and 1/2 → 3 × 1 + 2 = 5 → gives 5/2. Incorrect.
Right
3 and 1/2 → 3 × 2 = 6, then 6 + 1 = 7 → gives 7/2.
The rule: times the whole number by the bottom number, then add the top number.
Which game stage uses this
This is the Mixed numbers stage. You will start seeing these questions when you reach the pufferfish in the game.