Section 1
Modeling Decimal Subtraction
Property
To model subtraction, you start with the total amount (the minuend) and take away a part (the subtrahend) to find what is left (the difference).
In this Grade 5 Pengi Math lesson, students learn to subtract decimals through the thousandths place using the standard algorithm, including how to regroup when the top digit is smaller and annex zeros to create like units. Lessons build on place-value understanding and require aligning decimal points to subtract accurately and efficiently across decimals of different lengths.
Section 1
Modeling Decimal Subtraction
To model subtraction, you start with the total amount (the minuend) and take away a part (the subtrahend) to find what is left (the difference).
Section 2
Subtracting Decimals Using the Standard Algorithm
To subtract decimals using the standard algorithm, align the numbers vertically by their decimal points. Subtract each column from right to left, regrouping from the place value to the left when a top digit is smaller than the bottom digit. Place the decimal point in the answer directly below the decimal points in the problem.
Section 3
Annexing Zeros to Subtract Decimals
To subtract decimals with a different number of decimal places, annex (add) zeros to the right of the number with fewer decimal places until both numbers have the same number of places. This does not change the number's value (e.g., ).
Section 4
Subtracting Decimals to the Thousandths
To subtract decimals, align the numbers by their decimal points. Subtract as you would with whole numbers, starting from the rightmost place value, and regroup (borrow) when necessary. Place the decimal point in the difference directly below the decimal points in the numbers being subtracted.
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Section 1
Modeling Decimal Subtraction
To model subtraction, you start with the total amount (the minuend) and take away a part (the subtrahend) to find what is left (the difference).
Section 2
Subtracting Decimals Using the Standard Algorithm
To subtract decimals using the standard algorithm, align the numbers vertically by their decimal points. Subtract each column from right to left, regrouping from the place value to the left when a top digit is smaller than the bottom digit. Place the decimal point in the answer directly below the decimal points in the problem.
Section 3
Annexing Zeros to Subtract Decimals
To subtract decimals with a different number of decimal places, annex (add) zeros to the right of the number with fewer decimal places until both numbers have the same number of places. This does not change the number's value (e.g., ).
Section 4
Subtracting Decimals to the Thousandths
To subtract decimals, align the numbers by their decimal points. Subtract as you would with whole numbers, starting from the rightmost place value, and regroup (borrow) when necessary. Place the decimal point in the difference directly below the decimal points in the numbers being subtracted.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter