In math, there are a few words to keep an eye out for because it will give you directions for your equations...
"of" means times (×)
"is" means equals (=)
So you translate you sentence into an equation...
What is 2/3 of 8
what = 2/3 × 8
2/3 × 8 =
2/3 × 8/1 = 16/3
now reduce... 3 goes into 16 five times with 1 left over...
16/3 = 5 1/3