How each operation works
Take 1 1/2 + 3/4. First, mixed numbers become plain fractions: 1 1/2 is 3/2, because 1 whole is 2 halves, plus 1 more half.
Adding and subtracting need the same bottom number (denominator). The smallest number that 2 and 4 both go into is 4, so 3/2 becomes 6/4. Then add the tops and keep the bottom: 6/4 + 3/4 = 9/4. That’s 2 1/4, or 2.25.
Multiplying is the easy one: multiply the tops, multiply the bottoms. 2/3 × 3/4 = 6/12, which simplifies to 1/2.
Dividing is multiplying by the second fraction flipped. 3/4 ÷ 1/2 = 3/4 × 2/1 = 6/4 = 1 1/2.
Simplifying
A fraction is in simplest form when no number other than 1 divides both the top and the bottom. To get there, divide both by their greatest common factor. For 6/8 that’s 2, giving 3/4. Every answer here is simplified, and the steps say what it was divided by.
Three ways to write the answer
| Form | Example | Best for |
|---|---|---|
| Fraction | 9/4 | More math, homework answers |
| Mixed number | 2 1/4 | Measuring, recipes, woodworking |
| Decimal | 2.25 | Calculators, money, spreadsheets |
Limits
The math is exact, so very large numbers can run past what can be worked out precisely, and the calculator will say so. Decimals can have up to 9 places.