Using a zero as a placeholder so that both decimals ahve the same number of digits after their decimal point is a good strategy while adding decimals because it helps you line the decimals up in the correct way to get the correct sum.
So this is practically saying you need a spot where the number in between the decimal and number there is a place holder. Comment if you need more help
Convert your feet to inches. So 8 times by 12 = 96 inches if you have 3/4 of the board used. 3/4= .75 if you were to times 96 by .75 = 72 inches. So you used 72 inches and you have 24 inches left
now do 1/3= .33 times .33 by 24= 8 8 inches is how long you would give to Anthony's brother.