You will practice simple rounding of decimals to the nearest whole number and to the nearest tenth.
After completing this tutorial, you will be able to complete the following:
Rounding decimals to the nearest whole number and nearest tenth.
Students have learned how to read decimals, but it is important for students to understand the various functions of place value and the laws that govern rounding decimals to the nearest whole number and the nearest tenth.
Rounding is one way to estimate larger numbers. This Activity Object provides background and practice for rounding decimals. Students should have previously learned how to round whole numbers and decimals in upper elementary school; however, many students continue to inappropriately apply the rule for rounding.
Each digit in a number has a place value as shown in the place value chart below.
Based on the place value you are rounding to:
ˇ If the digit to the right is less than 5, do not change the "rounding digit," and drop all remaining digits to the right.
If that digit is greater than or equal to 5, add 1 to the "rounding digit," and drop all remaining digits to the right.
Round 2.46 to the nearest tenth.
In this example, the digit in the tenths place is 4. The digit to the right of the tenths place is a 6. Since 6 is greater than 5, we "round up" and change the digit to 5. The resulting number would be:
The following key vocabulary terms will be used throughout this Activity Object:
decimal - a number having one or more digits to the right of a decimal point
ˇ hundredths - according to place value, the position of the second digit to the right of the decimal point; also called hundredth's place
ˇ place value - the value of a digit in a number that depends on the digits place; for example, ones, tens, hundreds, thousands, etc.
ˇ rounding - one way of estimating by approximating a number to a specific place value
ˇ tenths - according to place value, the position of the first digit to the right of the decimal point; also called tenth's place
thousandths - according to place value, the position of the third digit to the right of the decimal point; also called thousandth's place
whole number - any of the numbers 0, 1, 2, 3, etc.
|Approximate Time||15 Minutes|
|Pre-requisite Concepts||Students should be familiar with decimals and place value, measuring metric lengths, and ordering decimals.|
|Type of Tutorial||Skills Application|
|Key Vocabulary||decimals, hundredths, place value|