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.
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.