Divide a Decimal by a Whole Number
Divide a Decimal by a Whole Number is a Grade 5 math skill from Illustrative Mathematics Chapter 5 (Place Value Patterns and Decimal Operations) where students perform long division with a decimal dividend by placing the decimal point in the quotient directly above the decimal point in the dividend, then dividing as with whole numbers. This splits the decimal amount into equal groups.
Key Concepts
Property To divide a decimal by a whole number, use long division. Place the decimal point in the quotient directly above the decimal point in the dividend. Then, divide as you would with whole numbers. $$ \text{dividend} \div \text{divisor} = \text{quotient} $$.
Examples $6.8 \div 2 = 3.4$ $7.5 \div 5 = 1.5$ $1.89 \div 9 = 0.21$.
Explanation Dividing a decimal by a whole number is very similar to regular long division. The most important step is to place the decimal point in your answer (the quotient) directly above the decimal point in the number being divided (the dividend). After that, you can ignore the decimal and divide as you normally would, from left to right. This process effectively splits the decimal amount into a specific number of equal groups.
Common Questions
How do you divide a decimal by a whole number?
Use long division. First, place the decimal point in the quotient (answer) directly above the decimal point in the dividend (the number being divided). Then divide the digits as you normally would with whole numbers.
What is an example of dividing a decimal by a whole number?
6.8 ÷ 2 = 3.4. Place the decimal in the quotient above the decimal in 6.8, then divide: 6 ÷ 2 = 3, 8 ÷ 2 = 4, giving 3.4. Another example: 1.89 ÷ 9 = 0.21.
What chapter covers decimal division in Illustrative Mathematics Grade 5?
Dividing a decimal by a whole number is covered in Chapter 5 of Illustrative Mathematics Grade 5, titled Place Value Patterns and Decimal Operations.
Why is the decimal point placement the most important step in decimal division?
Placing the decimal point correctly in the quotient ensures your answer has the right place value. If misplaced, the answer could be 10 times too large or too small.
How is decimal division similar to whole number division?
The process is identical once you place the decimal point. You divide digit by digit from left to right, bringing down remainders as with whole numbers. The decimal point in the quotient lines up with the decimal in the dividend.