Express missing number problems algebraically

1. A Pencil Problem - Determine the equation to use to solve a number problem
2. A Pencil Problem - Determine the equation to use to solve a number problem
3. Dad, Dave and Danny - Identify the correct algebraic expression for a given relationship
4. Dad, Dave and Danny - Identify the correct algebraic expression for a given relationship
5. Dad, Dave and Danny - Identify the correct algebraic expression for a given relationship
6. Mr Snags's Garden 3 - Identify the algebraic expression that describes a given relationship
7. A Pencil Problem - Determine the equation to use to solve a number problem
8. Dr Dan's Number Operations - Determine the equation to use to solve a number problem
9. Dr Dan's Number Operations - Determine the equation to use to solve a number problem
10. Pirate Pete's Problem - Derive and solve a simple linear expression
11. Down on Don's Farm - Develop then calculate an algebraic expression
12. Down on Don's Farm - Develop then calculate an algebraic expression
13. Schoolyard Stats: Formulate an algebraic expression
14. Nautical Numbers - Derive an algebraic expression
15. Number Quest - create expressions to match statements
16. Sum it up - Wal's wheels: expressions for cost
17. Schoolyard Stats: Formulate an algebraic expression
18. Schoolyard Stats: Formulate an algebraic expression
19. Schoolyard Stats: Formulate an algebraic expression
20. CD Changer: Substitute a value into an algebraic expression