When rounding, if the number is 5 or above, you round up, if 4 or below, round down.
The tenth's place is the number right after the decimal, and that is the only number we want after the decimal.
So, to round 9.46, we must get rid of the .06 so we are left with the 9 and the tenths place.
Because the 6 falls into the category of 5 or above, that means we round up.
When you do that, you add one to the number to the left, and the number that we just rounded becomes 0.
That means rounding 9.46 would be 9.50 and only having the tenths place would leave it as 9.5
Hope this helps!