Multiply the amount he feeds each horse by the number of horses.
Each horse gets 3/8 of a bale and there are 4 horses.
Total bales = 3/8 x 4
A whole number can also be written as a fraction by making the denominator ( bottom number) a 1, so 4 can be written as 4/1
So now you have 3/8 * 4/1
When you multiply fractions, multiply straight across ( multiply the two top numbers together and then the two bottom numbers together)
3/8 x 4/1 = (3*4) / (8*1) = 12/8 bales.
The answer is A