Question

in base five add the twenty eight plus nine

Answer 1

28 and 9 are not base 5 numbers

Answer 2

you can convert 28 and 9 to base 5 and then add. . .

Answer 3

(that's what "in base five add . . ." means.

Answer 4

still confused about base 5 Teacher gave the example 102 plus 21 in base 3 and the answer was 200. So how do you do it for base 5 28+9

Answer 5

In the case of 102 and 21. Those numbers are already expressed in base three.
102 = 9+2=11, and 21 = 6+1=7, so 11+7=18, which is 200 in base three.

Answer 6

28 = 5^2+3 so equals 103 in base 5.
Can you see what 9 is in base 5 @morenode ?

Answer 7

the questions is poorly worded. for sure.
Let's assume that 28 and 9 are "regular or base 10 numbers".

You can either add them together now and get 37 base 10. then convert that to base 5

or

you can convert them each to base 5 then do base 5 addition on them to get your result. the answer will be the same either way.

Answer 8

Sorry still not getting it how did you get that 28 is 103 in base 5

Answer 9

each place in the number stands for a power of the base.