1. Implementation
Review the mathematical concept.
Review the problem solving steps.
READ: Children read the part that is asking them to find something out.
UNDERSTAND: Children explain what they need to find out.
Children identify what information they will need to find it out.
Remove the coloured rectangle.
Children find the information they need to find it out.
CHOOSE A STRATEGY: Children identify strategies that they could use to find it out.
USE A STRATEGY: Children use a strategy to find it out.
Children record their thinking as they find it out.
CHECK: Children reread the part that asked them to find something out.
Children check that they have found it out.
Children check they have recorded their solution correctly.
Children follow the problem solving steps to solve the 2nd level of the problem, with minimal teacher guidance.
Children who solve the 2nd level, follow the problem solving steps to solve the 3rd level of the problem independently.
Children use the problems as a guide to create their own problem, either alone or in pairs/small groups.
Children solve their own problem.
Throughout the lesson, children share solution strategies.
At the end of the lesson, children explain how they created their own problems.

2. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
Gerry said that this number sentence is true: = 141 – 29.
Is he right? Why?
Gerry said that this number sentence is true: =
Is he right? Why?
Gerry said that this number sentence is true: =
Is he right? Why?
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19

3. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
What number makes this number sentence true?
153 – 87 = 38 + ____
What number makes this number sentence true?
= 67 + ____
What number makes this number sentence true?
186 – 73 = 91 +______
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19

4. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
has the same value as 43 + ____
has the same value as ____
has the same value as 17 +_____
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19

5. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
What number is missing from all of these number sentences?
56 + ___ = 64, ___ = 56, – 56 = ___
What number is missing from all of these number sentences?
13 + ___ = 28, ___ = 13, – 13 = ___
What number is missing from all of these number sentences?
55 + ___ = 73, ___ = 55, = ___
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19

6. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
Addition and Subtraction 22
Patterns and Algebra 19

7. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
Alan had 37 toy cars and 58 marbles. Betty had 29 toy cars and 66 marbles.
Do they have the same number of toys, or does one of the children have more toys?
Record a number sentence to show this.
Alan had 36 toy cars and 45 marbles. Betty had 17 toy cars and 55 marbles.
Do they have the same number of toys, or does one of the children have more toys?
Record a number sentence to show this.
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19

8. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
The Sharks scored 37 points in game 1 and 58 points in game 2.
The Goats scored 29 points in game 1 and 66 points in game 2.
Did they score the same number of goals?
Record a number sentence to show this.
The Sharks scored 24 points in game 1 and 47 points in game 2.
The Goats scored 17 points in game 1 and 54 points in game 2.
Did they score the same number of goals?
Record a number sentence to show this.
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19

9. Missing and Equivalent Number Sentences
Problem Solving
Missing and Equivalent Number Sentences
April wrote this correct number sentence.
= 121.
What number makes these number sentences true?
34 + ____ = 121
121 - ____ = 34
121 - ____ = 87
April wrote this correct number sentence.
= 101
What number makes these number sentences true?
85 + ____ = 101
101 - ____ = 85
101 - ____ = 16
Create your own problem! Now solve it!
Addition and Subtraction 22
Patterns and Algebra 19