Multiplying Decimals and Decimal Placement

In this video, Mr. J teaches fifth-grade students how to multiply decimals. The process is similar to multiplying whole numbers, with the key difference being the placement of the decimal in the final answer. The video includes four example problems, each increasing in complexity, to demonstrate the method. Students are encouraged to follow along and practice on their own. The video concludes with a reminder to count the digits to the right of the decimal in the original problem to correctly place the decimal in the answer.

What is the key difference between multiplying whole numbers and decimals?

• You need to line up the decimals.

• You must add extra zeros.

• You need to place the decimal in the correct position in the answer.

• You have to multiply each digit separately.

In the problem 1.3 x 0.5, how many decimal places should the answer have?

• No decimal places

• Two decimal places

• One decimal place

• Three decimal places

When multiplying 78.3 by 0.4, how many digits should be behind the decimal in the final answer?

• One digit

• Two digits

• Three digits

• Four digits

What is the first step in solving 5.1 x 3.8?

• Divide the numbers.

• Add the numbers first.

• Line up the decimals.

• Remove the decimals and multiply as whole numbers.

In the problem 5.1 x 3.8, what is the result of multiplying the whole numbers before placing the decimal?

• 1938

• 1.938

• 19.38

• 193.8

For the problem 31.2 x 8.17, how many placeholder zeros are needed for the second partial product?

• One

• Two

• Three

• None

In the multiplication of 31.2 by 8.17, how many digits should be to the right of the decimal in the final answer?

• Two digits

• Three digits

• One digit

• Four digits

What is the final step after multiplying the whole numbers in a decimal multiplication problem?

• Divide the result by 10.

• Place the decimal in the correct position.

• Add the numbers together.

• Subtract the smaller number from the larger.

Why is it important to count the digits to the right of the decimal in the original problem?

• To know how many digits to include in the answer.

• To determine the number of zeros to add.

• To decide the order of multiplication.

• To check if the answer is correct.

What should you do if the answer seems too large after multiplying decimals?

• Recalculate the multiplication.

• Subtract a number.

• Add more zeros.

• Check the decimal placement.