## Unit 1: Number, Estimation, and Computation

### What will your child learn in Unit 1?

In Unit 1, fifth graders will learn about decimal numbers and extend place value understanding to the thousandths place.  They will represent decimal numbers in different ways, such as written form, standard form, and expanded form. Fifth graders will primarily work on addition and subtraction of decimal numbers to the hundredths place. Students will use a variety of strategies to solve the problem. The solution methods range from using concrete models or drawings to strategies based on place value, meanings of operations, and number sense. In addition, students will be guided on how to solve addition and subtraction of decimal numbers using the standard algorithm. Students will understand why this method works and will apply this strategy to solve problems efficiently. Children go through different phases to quickly and accurately solve addition and subtraction problems.  Unit 1 will primarily focus on phases 2 and 3.

### What math strategies will your child use in Unit 1?

There are a variety of strategies to help solve addition and subtraction problems involving decimal numbers. The type of strategy depends on types of numbers used in the problem. The handout below gives an explanation of the different types of strategies.

Check out the videos below to see the math strategies in action. Most of the explanations are from students from our district. Thank you to the students for volunteering to explain their thinking!

### How can you support your child at home to reinforce the concepts taught in Unit 1?

There are several ways to have your child practice the math concepts at home. Try the following activities:

• Give your child an addition or subtraction problem involving decimal numbers and have them solve it mentally and explain their thinking verbally.
• Visit Deep Sea Duel to practice picking addends with a specified sum. Make sure to click Decimal On.
• Visit Base Blocks to have your child practice representing decimal numbers.
• Visit Math Racing Game to have your child practice comparing decimal numbers.
• Visit Adding Decimals Baseball Game to have your child practice adding decimal numbers.
• Have your child play Total Ten to practice adding decimal numbers.
• Have your child play Decimal Subtraction Spin to practice subtracting decimal numbers.
• Math Games for Home: Print the handouts to practice concepts through games.