How do you multiply a decimal?

Question

im in 6th grade and i dont know how!!!

example 7.2 times 2

ummm can you do it simpler i dont know how to multiply up and down either?

Answer 1

1.)Multiply the numbers just as if they were whole numbers:
-Line up the numbers on the right--do not align the decimal points.
-Starting on the right, multiply each digit in the top number by each digit in the bottom number, just as with whole numbers.
-Add the products.

2.)Place the decimal point in the answer by starting at the right and moving the point the number of places equal to the sum of the decimal places in both numbers multiplied.
Example

37.7 x 2.8 = ? --->

37.7 ( 1 decimal place )
x 2.8 ( 1 decimal place )
_______
3016
+754
105.56 ( 2 decimal places, move point 2 places left )

Hint: Use estimating to help you check the placement of the decimal point. You could round 37.7 to 40 and 2.8 to 3. It's easy to multiply 3 x 40 so you know your answer should be close to 120.

Here's a "mental math" shortcut: When multiplying a number by a multiple of ten, just move the decimal point one space to the right for every zero.

10 x 0.6284 = 6.284 (1 zero, 1 space right)
100 x 0.6284 = 62.84 (2 zeroes, 2 spaces right)
1000 x 0.6284 = 628.4 (3 zeroes, 3 spaces right)
10,000 x 0.6284 = 6284 (4 zeroes, 4 spaces right)
100,000 x 0.6284 = 62,840 (5 zeroes, 5 spaces right)

hope i helped

Answer 2

do it the same as you would without a decimal. so 72X2=144.

Now count how many numbers (using those you multiplied) are to the right of the decimal point (in this case 1 - 7.2 has 1 number to the right of the decimal and 2 has none to the right of the decimal)

Your answer should have the same amount of number to the right of the decimal as the original numbers did. so take the 144 and move the decimal point to make 1 number to the right and you have the answer 14.4

Answer 3

for 7.2 times 2 you would write 7.2 then directly underneath you would put 2. then multiply. then count the number of numbers behind the dcimal place ( in this case 1) and put the decimal that many places from the end of the above product.

Answer 4

Multiply as you would any other number then use the total number of decimals in the final result.

e.g. 72 * 2 =144 with total 1 decimal place = 14.4