1.work out 1/2 + 5/6
2.work out 3/4 x 2/7

, i have never been able to work these out although there so simple

1.  First find the LCD of the two fractions.
They share the denominator 6.
Turn 1/2 into a fraction with a denominator of 6.
2*3=6,  so 1*3=3
3/6
Now add.
Leave denominators alone,  but add numerators.
3+5=8
8/6
Now simplify.
Divide both by 2.
8/2=4
6/2=3
4/3 is your answer or 1 1/3
2.  Multiply straight across.
3*2=6
4*7=28
6/28
Simplify
You get 3/14 as your answer.