4th Grade Math: Addition and Subtraction Strategies

Understanding Addition and Subtraction Strategies

• Explain the reason behind the effectiveness of addition and subtraction strategies using place value and properties of operations.

Assessment Examples

• Students will write explanations for addition and subtraction strategies using place value and properties of operations.
• Examples of strategies may include:
  • Making tens
  • Counting on
  • Making zero pairs
  • Using doubles
  • Using number lines
• Students will provide specific examples to support their explanations.

Properties of Operations

• Properties of operations include:
  • Commutative property of addition
  • Associative property of addition
  • Distributive property of multiplication over addition

Place Value

• Understanding place value is essential for addition and subtraction strategies
• Place value involves:
  • Hundreds
  • Tens
  • Ones
  • Place value of digits in a number

Understanding Addition and Subtraction Strategies

• The concept involves explaining why addition and subtraction strategies work, relying on place value and the properties of operations.
• This knowledge is essential for developing a deep understanding of arithmetic operations.

Key Strategies

• Addition and subtraction strategies are based on the concept of place value, which is the value of a digit based on its position in a number.
• The properties of operations, such as commutative, associative, and distributive properties, also play a crucial role in these strategies.

Example Assessment

• Students will be given 5 problems to explain why addition and subtraction strategies work, providing examples to support their explanations.
• Examples of problems may include equations, such as 456 + 279, and asking students to explain the strategy used to solve the equation, referencing place value and the properties of operations.
• Other problems might involve subtracting multi-digit numbers, such as 945 - 437, and asking students to justify their subtraction strategy using place value and the properties of operations.