In a perfect world everything would be whole and we would not have to deal with parts of a whole. But in real life, a whole is often broken in parts. This is most evident in our monetary system–a cent is a part of a dollar, and we use a decimal to separate the whole (dollars) from the part (cents). Because money and decimals are a huge part of our daily lives, we need to be able to add, subtract, multiply, and divide decimals fluently.

In the activity Operations with Decimals, students use standard procedures to perform the four basic operations (addition, subtraction, multiplication, and division) with decimal numbers.

Students begin with models that help them to perform an operation, and then connect the standard procedure to the operation they performed on the model. For example, students use a grid to add two decimal numbers, and then use the standard procedure by aligning the decimal points in the numbers, and then adding the digits in the same place value. By the end of the activity students are exposed to real world situations they must solve by performing the appropriate operation(s) with decimal numbers.