Adding and subtracting fractions with like denominators

If denominators are the same, you add or subtract only the numerators and keep the denominator unchanged.

\frac{a}{m}+\frac{b}{m}=\frac{a+b}{m}

\frac{a}{m}-\frac{b}{m}=\frac{a-b}{m}

. Meaning: the parts are the same size (same denominator), so you count how many such parts you end up with. After computing, check whether the result is improper and simplify if possible (simplifying in depth comes later).

The common denominator stays the same

Only numerators are added or subtracted

You are counting equal-sized parts

Check the result: proper or improper fraction

Addition: example with a picture

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