Addition and subtraction 2

Students add three whole numbers whose sum is 20 or less by looking for pairs that make 10 or doubles.

1.OA.A.2: Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using ...

Students solve word problems that require adding three quantities, choosing efficient grouping strategies.

1.OA.A.2: Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using ...

Students apply different strategies to add three addends, explaining which grouping they chose and why.

1.OA.A.2: Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using ...

Students rewrite subtraction problems as missing-addend problems, understanding that 10 – 3 = ? is the same as 3 + ? = 10.

1.OA.B.4: Understand subtraction as an unknown-addend problem.

Students use the relationship between addition and subtraction to find unknown numbers in equations.

1.OA.B.4: Understand subtraction as an unknown-addend problem.

Students solve subtraction word problems by thinking about what number must be added to reach the total.

1.OA.B.4: Understand subtraction as an unknown-addend problem.

Students explore the meaning of the equal sign as showing that both sides have the same value, not just as a signal to compute.

1.OA.D.7: Understand the meaning of the equal sign as “has the same value/amount as” and determine if equations involving addition...

Students determine whether equations like 5 + 3 = 8 and 4 + 2 = 5 + 1 are true or false, justifying their answers.

1.OA.D.7: Understand the meaning of the equal sign as “has the same value/amount as” and determine if equations involving addition...

Students find missing values that make equations true, strengthening their understanding of equality.

1.OA.D.7: Understand the meaning of the equal sign as “has the same value/amount as” and determine if equations involving addition...

Students use counting on from the larger addend and counting back as efficient strategies for addition and subtraction.

Students use subitizing (instantly recognizing small quantities) and known facts to solve addition and subtraction problems quickly.

Students review all learned strategies and select the most efficient one for a given problem, building computational fluency.