Decimals

Decimals are a way of expressing parts of a whole. They are based on the powers of 10. The digits to the right of the decimal point indicate smaller and smaller parts of a whole number. The first digit to the right of the decimal point represents tenths, the second digit represents hundredths, the third digit represents thousandths, and so on.

Key Concepts:

1. Place Value: In a decimal number, each digit has a place value based on its position from the decimal point. For example, in the number 123.456, the digit 4 is in the tenths place, so its value is 4/10.
2. Comparing Decimals: When comparing decimals, start from the left and compare the digits in each place value. If the digits are the same, move to the next place value. The decimal with the larger digit at the first differing place value is greater.
3. Adding and Subtracting Decimals: When adding or subtracting decimals, be sure to line up the decimal points. If one number has fewer decimal places, you can add zeros to the end to make them equal. Then, perform the addition or subtraction as you would with whole numbers.
4. Multiplying and Dividing Decimals: When multiplying decimals, ignore the decimal points and multiply the numbers as if they were whole numbers. Then, count the total number of decimal places in the original numbers and place the decimal point in the product that many places from the right. When dividing decimals, move the decimal point to the right in both the dividend and the divisor until the divisor is a whole number. Then, perform the division as if they were whole numbers and place the decimal point in the quotient directly above the decimal point in the dividend.

Practice Problems:

1. What is 5.326 in word form?
2. Compare 3.25 and 3.5.
3. Add 6.72 and 3.14.
4. Subtract 4.6 from 10.25.
5. Multiply 2.5 by 3.6.
6. Divide 8.64 by 2.4.

[Decimals] Related Worksheets and Study Guides:

• DecimalsMathematics • Fourth Grade
• Ordering DecimalsMathematics • Fifth Grade
• Decimals/FractionsMathematics • Fourth Grade