These exercises and activities are for students to use independently of the teacher to practice and develop their number properties.

Use compatible numbers to solve addition problems with decimal fractions (tenths) (Exercises 1-5)

Use compatible numbers to solve subtraction problems with decimal fractions (tenths) (Exercise 6)

Addition and Subtraction, AM (Stage 7)

### Prior knowledge.

- Explain place value with decimals
- know combinations of tenths that add to one
- Use the idea of compatible numbers to add whole numbers

### Background

This activity uses the strategy of compatible numbers to add decimal numbers. Students at this stage should be familiar with using the strategy with whole numbers.

### Comments on the Exercises

**Exercise 1**Asks students to identify tenths that add to one.

**Exercise 2**

Asks students to use <, > in sentences to show they can identify tenths that add to one, are less than or more than one.

**Exercises 3 – 5**

Asks students to solve problems requiring addition of decimal fractions (tenths) using compatible numbers strategy.

Exercise 3: All numbers are less than one and students make numbers up to one.

Exercise 4: Compatible numbers include one number less than one and one number greater than one.

Exercise 5: Compatible numbers could both be greater than one.

**Exercise 6**Asks students to use compatible numbers in subtraction (decimal fractions).