In this Grade 8 lesson from Saxon Math Course 3, students learn how to multiply and divide decimal numbers using pencil-and-paper methods, including counting decimal places to position the decimal point in a product and aligning the decimal point when dividing by a whole number. The lesson also covers multiplying and dividing decimals by powers of 10, squaring decimal numbers, and applying these skills to real-world problems such as calculating costs with fractional pound measurements.
Section 1
📘 Multiplying and Dividing Decimal Numbers
When dividing by a decimal number we take an extra step to make an equivalent problem in which the divisor is a whole number.
Next, you’ll master these skills through worked examples on multiplication and division, including word problems about cost and miles per gallon.
Section 2
Multiplying Decimal Numbers
To multiply decimals, we first multiply the numbers as if they are whole. Then, we count the total number of decimal places in the original factors to position the decimal point correctly in the final product.
Think of it as a magic trick! Make the decimals vanish, multiply the whole numbers, and then poof! Bring the decimal point back by counting the total spots from the original numbers. It’s just counting!
Section 3
Dividing Decimals By Wholes
When dividing by a whole number, the decimal point in the quotient is placed directly above the decimal point of the dividend. Fill any empty places in the quotient with zeros if necessary.
This is the easy kind of decimal division! Just float the decimal point straight up into your answer's spot. Then, divide like you normally would. Zeros are your best friends for holding empty places!
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Section 1
📘 Multiplying and Dividing Decimal Numbers
When dividing by a decimal number we take an extra step to make an equivalent problem in which the divisor is a whole number.
Next, you’ll master these skills through worked examples on multiplication and division, including word problems about cost and miles per gallon.
Section 2
Multiplying Decimal Numbers
To multiply decimals, we first multiply the numbers as if they are whole. Then, we count the total number of decimal places in the original factors to position the decimal point correctly in the final product.
Think of it as a magic trick! Make the decimals vanish, multiply the whole numbers, and then poof! Bring the decimal point back by counting the total spots from the original numbers. It’s just counting!
Section 3
Dividing Decimals By Wholes
When dividing by a whole number, the decimal point in the quotient is placed directly above the decimal point of the dividend. Fill any empty places in the quotient with zeros if necessary.
This is the easy kind of decimal division! Just float the decimal point straight up into your answer's spot. Then, divide like you normally would. Zeros are your best friends for holding empty places!
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter