Add and subtract fractions with the same denominator, within 1

What this means, in plain words

The denominator is the number underneath the line in a fraction. It tells you how many equal parts the whole was split into.

A fraction describes part of a whole, or part of a set, once the whole has been split into equal pieces.

Addition puts amounts together to find a total. Subtraction takes one amount away, or finds the difference between two.