Mathematics, Operations (+, -, x, /, etc.), Fractions
Grade 5- 8
Students learn how to multiply decimals.
Facts to Know
You multiply decimals the same way you multiply whole numbers. Also, the decimal points do not have to be lined up. However, you must be careful to correctly place the decimal point in the product for multiplication. The number of decimal places in the answer must equal the total number of places to the right of the decimal point in the problem.
Decimal Points in the Final Answer
Multiplying decimals is the same as multiplying whole numbers. The key is to count the decimal places in each factor.
Sample: 458 x 7.3 = ?
Step 1 Line up the digits.
Step 2 Multiply as with whole numbers.
Step 3 Count the decimal places in each factor. The product must have an equal number of decimal places as the problem.
45.8 |
x 7.3 |
____ |
1374 |
+ 32060 |
3,343.4 |
21.45 |
x 0.0321 |
_______ |
2145 |
42900 |
+ 643500 |
0.688545 |
2.54 | (2 decimal places) |
x 4 | (0 decimal places) |
____ | |
10.16 | (2 decimal places) |