Theory
How do you add fractions with the same denominator?
In a fraction, the denominator tells you how many equal parts the whole is divided into.
The numerator tells you how many of those parts you have.
Fractions with the same denominator have the same denominator, so the parts are the same size. Add only the numerators and keep the denominator the same.
- Add the numeratorsAdd the numerators together.
When adding, you combine two amounts.
You can count from left to right, but with larger numbers it is often easier to make a round number first.
If you use part of the second number to fill up the first number, then after that you only need to add the rest.
- See if you can add on in a smart wayWith larger numbers, you can often make a round number first.
- Add the restThen add what is left.
- See if you can add on in a smart way
- Write the new fractionUse the sum of the numerators as the new numerator. The denominator stays the same.
Calculate
312 +
812.
- Add the numerators3 + 8 = 11
- See if you can add on in a smart way3 + 7 = 10, dus er blijft 1 over.
- Add the rest10 + 1 = 11.
- See if you can add on in a smart way
- Write the new fractionThe new numerator is 11 and the denominator stays 12: 1112.