Common Core MATH 1 NBT 6 Grade 1 Number And Operations In Base Ten Use Place Value Understanding And Properties Of Operations To Add And Subtract

Number And Operations In Base Ten: Use Place Value Understanding And Properties Of Operations To Add And Subtract.

Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), 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.