U4L1 Number Puzzles
U4L2 Keeping the Equation Balanced
U4L3 Balanced Moves
U4L4 More Balanced Moves
U4L5 Solving Any Linear Equation
U4L6 Strategic Solving
U4L7 All, Some, or No Solutions
U4L8 How Many Solutions?
U4L9 When Are They the Same?
U4L10 On or Off the Line?
U4L11 On Both of the Lines
U4L12 Systems of Equations
U4L13 Solving Systems of Equations
U4L14 Solving More Systems
U4L15 Writing Systems of Equations
U4L16 Solving Problems with Systems of Equations