Rounding

Rounding is the process of approximating a number to a certain place value. This is often done to make numbers easier to work with or understand. When rounding a number, you are essentially finding the closest value to the original number that has a specified number of digits or decimal places.

Rules for Rounding Whole Numbers

When rounding whole numbers, you typically round to the nearest tens, hundreds, thousands, etc. The general rule is:

• If the digit to the right of the place value you are rounding to is 5 or greater, you round up.
• If the digit to the right of the place value you are rounding to is less than 5, you round down.

Example:

Rounding 348 to the nearest tens:

1. Identify the digit in the tens place, which is 4.
2. Look at the digit to the right of the tens place, which is 8.
3. Since 8 is 5 or greater, round up.
4. The rounded number is 350.

Rules for Rounding Decimals

When rounding decimals, you also use the same rules as for whole numbers. The only difference is that you are rounding to a certain decimal place instead of a place value.

Example:

Rounding 3.726 to the nearest hundredth:

1. Identify the digit in the hundredths place, which is 2.
2. Look at the digit to the right of the hundredths place, which is 6.
3. Since 6 is 5 or greater, round up.
4. The rounded number is 3.73.

Study Guide

When studying rounding, make sure to practice rounding both whole numbers and decimals to different place values. Here are some key points to remember:

• Understand the rules for rounding whole numbers and decimals.
• Practice identifying the digit in the specified place value and determining whether to round up or down based on the digit to the right of it.
• Work on real-world problems that require rounding, such as estimating costs or quantities.

By mastering rounding, you will be better equipped to work with numbers in everyday situations and in more advanced mathematical concepts.