# Unit 4 Relating Multiplication to Division (Family Materials)

In this unit, students make sense of division and learn to multiply and divide whole numbers within 100. They also use the four operations to represent and solve two-step word problems. Students work toward these end-of-year goals:

fluently multiply and divide within 100

know from memory all products of two one-digit numbers

Near the end of the unit, ask your student to find answers to the following problems:

Questions that may be helpful as they work:

How did you break up the problem to make it easier for you to solve?

Can you rewrite the division problem as a multiplication problem?

## Section A What is Division?

In this section, students think about division in terms of equal-size groups, just as they have done with multiplication. For instance, the expression

30 objects put into 5 equal groups

30 objects put into groups of 5

## Section B Relate Multiplication and Division

In this section, students make connections between the result of division and the missing factor in a multiplication equation.

For example, the value of

Students also learn to use properties of operations to multiply.For example, if they know

They can also decompose (or break apart) the 7 in

## Section C Multiplying Larger Numbers

In this section, students use different strategies to multiply larger numbers. First, they multiply a single-digit number by a multiple of 10, relying on what they know about place value. For instance,

Students see that it is helpful to break apart the two-digit numbers by place value, into tens and ones. For example,

base-ten blocks or diagrams

gridded area diagram

ungridded area diagram

## Section D Dividing Larger Numbers

In this section, students divide larger numbers. They continue to use the relationship between multiplication and division and their understanding of place value to find quotients. For example, to find the value of