Rounding Decimals

In this section, we will focus on understanding decimal place value, how to compare the size of two or more decimals, and how to round decimals. We will begin with an explanation of how to set up an expanded place value chart with place values to the right of the ones’ place. As we move to the right of the ones’ place, we encounter a decimal point ".", followed by the tenths place, hundredths place, thousandths place,… We will again practice writing place values for given digits in a number. Next, we will learn to compare the relative size of two decimals. We accomplish this task by comparing corresponding digits until they differ in value. Once this happens, the number with the larger corresponding digit will be the larger number. For example, 0.004123 is less than 0.004131. The fifth corresponding digit after the decimal point is a two vs. a three. The three is larger and belongs to the bigger number. Therefore, we can say 0.004123 < 0.004131. Lastly, we will learn how to round when decimals are involved. This is simply a slightly modified version of rounding with whole numbers.