Lesson 4

The purpose of this lesson is for students to explore the relationships between different ways of representing a decimal using the context of weights and a balance.

In previous lessons, students represented 1 tenth, 1 hundredth, and 1 thousandth as fractions, decimals, with words and in expanded form. The purpose of this optional lesson is to use the context of weight to further understand and relate these different ways to represent a decimal number (MP2). The weights make the expanded form of a decimal tangible and also help to explain the word form which, in the weight context, represents using all weights of the smallest size (one thousandth for a decimal to the thousandths). 

The third activity in the lesson focuses on the multiplicative relationships between the different place values, again shown by the weights. In particular, 1 tenth is equivalent to 10 hundredths and 1 hundredth is equivalent to 10 thousandths. These relationships will be explored further in the next unit, but students use these relationships throughout this unit as they work with decimals and perform arithmetic with decimals. 

• If needed, give students access to the hundredths grid.

What connections did students make between the different strategies shared? What questions did you ask to help make the connections more visible?