# Compatible decimal fractions

Purpose

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

Achievement Objectives
NA4-2: Understand addition and subtraction of fractions, decimals, and integers.
Specific Learning Outcomes

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)

Description of Mathematics

Addition and Subtraction, AM (Stage 7)

Required Resource Materials
Practice exercises with answers (PDF or Word)
Activity

### 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.

Exercise 1

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).

Attachments