AK.1.NBT. Number and Operations in Base Ten
Use place value understanding and properties of operations to add and subtract.
1.NBT.4. Add using numbers up to 100 including adding a two-digit number and a one-digit number and adding a two-digit number and a multiple of 10.
1.NBT.4.a. Use concrete models or drawings and strategies based on place value; properties of operations; and/or relationship between addition and subtraction.
1.NBT.4.b. Relate the strategy to a written method and explain the reasoning used.
1.NBT.6. Subtract multiples of 10 up to 100.
1.NBT.6.a. Use concrete models or drawings; strategies based on place value; properties of operations; and/or the relationship between addition and subtraction.
1.NBT.6.b. Relate the strategy to a written method and explain the reasoning used.
AK.1.OA. Operations and Algebraic Thinking
Add and subtract using numbers up to 20.
1.OA.5. Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).
1.OA.6. Add and subtract using numbers up to 20, demonstrating fluency for addition and subtraction up to 10. Use strategies such as
1.OA.6.a. Counting on
1.OA.6.b. Making ten (8 + 6 = 8 + 2 + 4 = 10 + 4 = 14)
1.OA.6.e. Creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
Represent and solve problems involving addition and subtraction.
1.OA.1. Use addition and subtraction strategies to solve word problems (using numbers up to 20), involving situations of adding to, taking from, putting together, taking apart and comparing, with unknowns in all positions, using a number line (e.g., by using objects, drawings and equations). Record and explain using equation symbols and a symbol for the unknown number to represent the problem.
Understand and apply properties of operations and the relationship between addition and subtraction.
1.OA.4. Understand subtraction as an unknown-addend problem. For example, subtract 10 - 8 by finding the number that makes 10 when added to 8.