Question 1210257
<br>
One square foot
= 1 foot by 1 foot
= 12 inches by 12 inches
= 12*12 = 144 square inches<br>
The "breakdown method": (NOT a standard mathematical term -- but a valid method you are apparently learning....)<br>
81 square inches = 72 square inches plus 9 square inches<br>
72 square inches = 1/2 of 144 square inches, so 72 square inches weighs 1/2 as much as 144 square inches -- 1/2 of 8.976 pounds = 4.488 pounds<br>
9 square inches = 1/8 of 72 square inches, so 9 square inches weighs 1/8 as much as 72 square inches -- 1/8 of 4.488 pounds = 0.561 pounds<br>
Weight of 81 square inches of the material
= weight of 72 square inches plus weight of 9 square inches
= 4.488 + 0.561 pounds = 5.049 pounds<br>
A summary without so many words to help see where the "1/2" and "1/8" came from:<br>
81 = 72+9 = {{{red(1/2)}}} of 144 plus {{{red(1/8)}}} of 72<br>