Chapter 1: Addition and Subtraction; Worked Example 2 (p. 2) Chapter 1: Addition and Subtraction; Practice Questions (p. 5) Chapter 11: Shapes and Patterns; Worked Example 2 (p. 131) Chapter 11: Shapes and Patterns; Challenging Problems (p. 138) Chapter 13: Review Questions 2; Challenging Problems (p. 155)(p.98)