This is an assessment of the skill to mentally add 10 or 100 to a given number 100-900, and mentally subtract 10 or 100 from a given number 100-900. (Common Core Standard 2.NBT.B.8)
There are five pages.
*Page 1: 10 more
*Page 2: 100 more
*Page 3: 10 less
*Page 4: 100 less
*Page 5: 10 more/10 less/ 100 more/ 100 less
There are three assessments per page in order to save paper. I usually stretch this skill over a week's time and will give one assessment per day. For students who have difficulty with this skill, I will give them a highlighter and have students highlight either the tens or hundreds place (depending upon which digit is being added to or taken away from). Then, I will have the students look for a pattern. (i.e. If we are mentally adding ten, the tens place will go up by one to the next digit.)