Multiplying and Dividing Decimals
Practice computing with decimal factors and quotients
Multiplying and Dividing Decimals
Practice computing with decimal factors and quotients
Math - Grade 6-8
- 1
Multiply: 3.4 x 2.5
Ignore the decimals first, then count the total decimal places in the factors.
The product is 8.5. You can multiply 34 x 25 = 850 and then place the decimal two places from the right. - 2
Multiply: 0.6 x 0.08
The product is 0.048. Multiply 6 x 8 = 48 and place the decimal three places from the right because there are three decimal places total in the factors. - 3
Multiply: 12.3 x 0.4
A number times 0.4 should be less than half of the original number.
The product is 4.92. Multiply 123 x 4 = 492 and place the decimal two places from the right. - 4
Multiply: 5.75 x 1.2
The product is 6.9. Multiply 575 x 12 = 6900 and place the decimal three places from the right. - 5
Find the area of a rectangle with length 4.8 cm and width 2.5 cm.
Area of a rectangle equals length times width.
The area is 12 square centimeters. Multiply 4.8 x 2.5 to get 12. - 6
Divide: 7.2 divided by 3
The quotient is 2.4. Since 72 tenths divided by 3 equals 24 tenths, the answer is 2.4. - 7
Divide: 15.75 divided by 5
You can think of 1575 hundredths divided by 5.
The quotient is 3.15. Dividing 15.75 by 5 gives 3.15 exactly. - 8
Divide: 0.84 divided by 0.2
The quotient is 4.2. Multiply both numbers by 10 to make the divisor a whole number, so 0.84 divided by 0.2 becomes 8.4 divided by 2. - 9
Divide: 6.72 divided by 0.8
Move the decimal in both numbers the same number of places.
The quotient is 8.4. Multiply both numbers by 10 so the problem becomes 67.2 divided by 8. - 10
Divide: 3.375 divided by 1.5
The quotient is 2.25. Multiply both numbers by 10 to get 33.75 divided by 15, then divide. - 11
A bag of trail mix weighs 2.4 kilograms. It is split equally into 6 smaller bags. How many kilograms are in each smaller bag?
This is an equal-sharing division problem.
Each smaller bag has 0.4 kilograms. Divide 2.4 by 6 to find the amount in each bag. - 12
A rope that is 9.6 meters long is cut into pieces that are each 0.8 meter long. How many pieces are made?
There are 12 pieces. Divide 9.6 by 0.8, or think of 96 divided by 8 after multiplying both numbers by 10. - 13
Estimate first, then solve: 4.19 x 3.2
Round 4.19 to 4 and 3.2 to 3 before multiplying.
A reasonable estimate is 4 x 3 = 12. The exact product is 13.408, which is close to the estimate. - 14
Estimate first, then solve: 8.64 divided by 2.4
A reasonable estimate is 9 divided by 2.5, which is about 3.6. The exact quotient is 3.6. - 15
A student says that 2.5 x 0.4 = 10 because 25 x 4 = 100. Explain the mistake and give the correct answer.
The product of a number and 0.4 should be less than the original number if the original number is positive.
The mistake is that the decimal places were ignored at the end. Since 2.5 has one decimal place and 0.4 has one decimal place, the product must have two decimal places. The correct answer is 1.0, or 1.