1.NBT.4:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.
K.OA.2:
Operations And Algebraic Thinking
Understand Addition As Putting Together And Adding To, And Under- Stand Subtraction As Taking Apart And Taking From.
Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.
