Grade Level: K Skill: Problem Solving Topic: Checking Answers Goal: Make precise calculations and check the validity of the results in the context of the problem Skill Description: Be able to perform calculations to find the exact answers. Use answers to double check calculations. Know how to re-work problem using answer to double check result.

### Sample Problems

 (1) What is 4+2 = (2) Double check the answer by subtracting 6-4 = (3) What is 9-5= (4) Double check by adding 4+5=

 (1)

### Extra Help Problems

 (1) Double check the following problems. Fill in the blnk with the correct number. 4+5=9 9-_=4 (2) 6+6=12 12-6=_ (3) 10+5=15 _-5=10 (4) 20+2=22 22-_=20 (5) 10-3=7 7+3=_ (6) 15-4=11 11+4=_ (7) 23-5+18 18+5=_ (8) 14-7=7 7+7=_ (9) It was 8 o’clock two hours ago. It is ten o’clock right now. Move the ________ hand two numbers backwards to check answer. (10) It is 2:30 p.m. now. It will be 5:30 p.m. in three hours. Move the ________ hand three numbers forward to check answer. (11) Four dimes equal \$0.40. To double check my answer I will: Add the dimes again Subtract counting by tens (12) Two quarters and one dime equal \$0.60. To double check my answer I will : Add the money again Subtract the coins.