Use addition and subtraction within 20 to flexibly, efficiently | Use addition and subtraction within 20 to flexibly, efficiently, and accurately solve word problems
involving situations of adding to, taking from, putting together, taking apart, and comparing, with
unknowns in all positions, e.g., by using objects, drawings, and/or equations with a symbol for the
unknown number to represent the problem. | 1.OA.A.1 |
| | Flexibly, efficiently, and accurately solve word problems that call for addition of three whole
numbers whose sum is less than or equal to 20, e.g., by using objects, drawings, and/or equations
with a symbol for the unknown number to represent the problem. | 1.OA.A.2 |
Apply and extend properties of operations by selecting and demonstrating… | Apply and extend properties of operations by selecting and demonstrating strategies to add and
subtract. | 1.OA.B.3 |
Demonstrate understanding of subtraction as an unknown-addend problem | Demonstrate understanding of subtraction as an unknown-addend problem. | 1.OA.B.4 |
Extend and apply counting strategies to addition and subtraction | Extend and apply counting strategies to addition and subtraction (e.g., by counting on 2 to add 2). | 1.OA.C.5 |
| | Flexibly, efficiently, and accurately add and subtract within 20, for addition and subtraction within
10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14,
decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the
relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 =
4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known
equivalent 6 + 6 + 1 = 12 + 1 = 13). | 1.OA.C.6 |
Demonstrate understanding of the meaning of the equal sign | Demonstrate understanding of the meaning of the equal sign, and determine if equations involving
addition and subtraction are true or false. | 1.OA.D.7 |
Determine the unknown whole number in an addition or subtraction equation… | Determine the unknown whole number in an addition or subtraction equation relating three whole
numbers. | 1.OA.D.8 |