## Math Unit 1

Multiplicative Thinking

Unit 1 begins the year with a study of multiplication and division, focusing in particular on

The models and strategies appearing in Unit 1 help students to review and re-access what they learned in Grade 3. These include the open number line, array, and area model.

**models**,**strategies**and multiplicative comparisons. The unit is made up of four modules and will last about one month.The models and strategies appearing in Unit 1 help students to review and re-access what they learned in Grade 3. These include the open number line, array, and area model.

**The Open Number LIne**

This model is used to show repeated addition as a bridge to the array.

**The Array or Area Model**

In the area model for multiplication, the total area of the rectangle represents the product, and the two dimensions represent the factors.

Because multiplication and division are inverse operations, the same model can be used to illustrate division.

The Ratio Table

The ratio table is used to build both multiplicative thinking and proportional reasoning.Students fill in tables for situations with constant ratios such as when one row in a box has 8 crayons and there are 4 rows. Later, the ratio table will become a tool for students to use in problem solving to compute multiplication, division, and fraction problems.

The ratio table is used to build both multiplicative thinking and proportional reasoning.Students fill in tables for situations with constant ratios such as when one row in a box has 8 crayons and there are 4 rows. Later, the ratio table will become a tool for students to use in problem solving to compute multiplication, division, and fraction problems.