This mixed number Each whole apple contains two half apples. Your two whole apples are also four half apples. Four half apples plus one half apple is five half apples. So you have 5/2 apples.
To put this another way: to turn a mixed number into a fraction, multiply the whole number by the denominator (the bottom part), and add the result to the numerator (the top part).
2 1/2 = ?
Multiply the whole number by the denominator.
The whole number is 2.
The denominator is 2.
2 x 2 = 4.
Add the result to the numerator:
The numerator is 1.
4 + 1 = 5
The numerator is 5. The denominator remains 2.
2 1/2 = 5/2