Unit 3: Operations and Algebraic Thinking
In this unit, students will:
• Explore, understand, and apply the commutative and associative properties as strategies for solving addition problems.
• Share, discuss, and compare strategies as a class.
• Connect counting on to solving subtraction problems. For the problem “15 – 7 = ?” they think about the number they have to count on from 7 to get to 15.
• Work with sums and differences less than or equal to 20 using the numbers 0 to 20.
• Identify and then apply a pattern or structure in mathematics. For example, pose a string of addition and subtraction problems involving the same three numbers chosen from the numbers 0 to 20, such as 4 + 13 = 17 and 13 + 4 = 17.
• Analyze number patterns and create conjectures or guesses.
• Choose other combinations of three numbers and explore to see if the patterns work for all numbers 0 to 20.
• Understand that addition and subtraction are related and that subtraction can be used to solve problems where the addend is unknown.
• Use the strategies of counting on and counting back to understand number relationships.
• Organize and record results using tallies and tables.
• Determine the initial and the change unknown.
• Explore, understand, and apply the commutative and associative properties as strategies for solving addition problems.
• Share, discuss, and compare strategies as a class.
• Connect counting on to solving subtraction problems. For the problem “15 – 7 = ?” they think about the number they have to count on from 7 to get to 15.
• Work with sums and differences less than or equal to 20 using the numbers 0 to 20.
• Identify and then apply a pattern or structure in mathematics. For example, pose a string of addition and subtraction problems involving the same three numbers chosen from the numbers 0 to 20, such as 4 + 13 = 17 and 13 + 4 = 17.
• Analyze number patterns and create conjectures or guesses.
• Choose other combinations of three numbers and explore to see if the patterns work for all numbers 0 to 20.
• Understand that addition and subtraction are related and that subtraction can be used to solve problems where the addend is unknown.
• Use the strategies of counting on and counting back to understand number relationships.
• Organize and record results using tallies and tables.
• Determine the initial and the change unknown.