Question

1/4 + 1/2

Answer 1

2/6

Answer 2

nope
1/2 = 2/4, so you have
1/4 + 2/4 = 3/4

when you multiply, you multiply tops and bottoms.
when you add, you must first find a common denominator, then add the numerators.

in your case,
1/4 = 0.25
1/2 = 0.50
1/4 + 1/2 = 0.75
but 2/6 = 0.3333...