Section 1
Add and Subtract Decimals
Property
To add or subtract decimals, line up the numbers by their decimal points. Then, add or subtract as you would with whole numbers, bringing the decimal point straight down into your answer.
In this Grade 6 lesson from enVision Mathematics Chapter 1, students develop fluency with adding, subtracting, and multiplying decimals, focusing on aligning place values, annexing zeros as placeholders, and determining decimal placement in products. The lesson covers Common Core standard 6.NS.B.3 through real-world contexts such as race times and area calculations. Students also learn to estimate with decimals to verify the reasonableness of their answers.
Section 1
Add and Subtract Decimals
To add or subtract decimals, line up the numbers by their decimal points. Then, add or subtract as you would with whole numbers, bringing the decimal point straight down into your answer.
Section 2
Multiply Decimals
To multiply decimal numbers, first multiply the numbers as if they are whole numbers, ignoring the decimal points. The product will have the same number of decimal places as the total number of decimal places in the factors.
Section 3
Applying the Rule for Decimal Point Placement
When multiplying decimals, count the total decimal places in both factors to determine decimal places in the product:
If factor 1 has decimal places and factor 2 has decimal places, then the product has decimal places.
When the product doesn't have enough digits, insert leading zeros after the decimal point.
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Section 1
Add and Subtract Decimals
To add or subtract decimals, line up the numbers by their decimal points. Then, add or subtract as you would with whole numbers, bringing the decimal point straight down into your answer.
Section 2
Multiply Decimals
To multiply decimal numbers, first multiply the numbers as if they are whole numbers, ignoring the decimal points. The product will have the same number of decimal places as the total number of decimal places in the factors.
Section 3
Applying the Rule for Decimal Point Placement
When multiplying decimals, count the total decimal places in both factors to determine decimal places in the product:
If factor 1 has decimal places and factor 2 has decimal places, then the product has decimal places.
When the product doesn't have enough digits, insert leading zeros after the decimal point.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter