Addition and subtraction 1

Students solve word problems where a quantity is added to a starting amount, using objects, drawings, and equations.

1.OA.A.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting to...

Students solve put-together problems where two groups are combined, representing their thinking with drawings and number sentences.

1.OA.A.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting to...

Students solve take-from word problems within 20, connecting the action of removing to subtraction equations.

1.OA.A.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting to...

Students solve taking-apart problems by finding a missing part when the total and one part are known.

1.OA.A.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting to...

Students solve comparison problems asking how many more one group has than another, using matching and subtraction.

1.OA.A.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting to...

Students solve comparison problems asking how many fewer, connecting the language of fewer to subtraction.

1.OA.A.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting to...

Students discover the commutative property of addition: that numbers can be added in any order and the sum stays the same.

1.OA.B.3: Apply properties of operations as strategies to add and subtract.

Students use the associative property to group three addends in different ways, choosing pairs that are easiest to add first.

1.OA.B.3: Apply properties of operations as strategies to add and subtract.

Students apply the commutative and associative properties as strategies to make addition and subtraction more efficient.

1.OA.B.3: Apply properties of operations as strategies to add and subtract.

Students use counting on from the larger number as a strategy for addition and for finding differences.

Students decompose an addend to make a ten, then add the remaining ones, building fluency with the make-ten strategy.

Students select from counting on, making ten, and decomposing strategies to add and subtract within 20, explaining their reasoning.