We know that a carton holds 24 bottles of juice and we want to find out how many juice bottles are in 15 cartons. To solve this problem we have to use multiplication.
24 * 15 = # of juice.
_____________________________________________________
Set up the long multiplication.
Calculate 4 x 5, which is 20.
Since 20 is two-digit, we carry the first digit 2 to the next column.
Calculate 2 x 5, which is 10. Now add the carry digit of 2, which is 12.
Since 12 is two-digit, we carry the first digit 1 to the next column.
Bring down the carry digit of 1.
Calculate 4 x 1, which is 4.
Calculate 2 x 1, which is 2.
Calculate 120 + 240, which is 360
Therefore, 24 x 15 = 360.
