1 EASY Round 24 to the nearest 10.

 2 EASY Round 40 to the nearest 10.

 3 EASY Round 148 to the nearest 10.

 4 EASY Round 72 to the nearest 10.

 5 MEDIUM Add 16 to 32, then round your answer to the nearest 10.

 6 MEDIUM Round 35 to the nearest 10.

 7 MEDIUM What digit must every number that is rounded to the nearest 10 end with?

 8 HARD Ms. Steinar assigned Jack a two-digit even number. Jack rounded his number to the nearest 10, added the result to 12, and rounded the sum again to the nearest 10. If the final number is 50, which of the following CANNOT be Jack's original number? 3436384042

 9 HARD John rounds 48 to the nearest ten, then rounds 54 to the nearest ten, then adds his two numbers together. Jean adds 48 and 54, then rounds the result. Who's final number is bigger, John's or Jean's? JohnJeanTheir numbers are equalImpossible to determineNone of the above

 10 HARD Jack rounds 27 to the nearest 10, then rounds 35 to the nearest 10, then adds the two numbers. Jacques adds 27 and 35, then rounds the sum to the nearest 10. Who's final number is bigger, Jack's or Jacques's? JackJacquesTheir numbers are equalImpossible to determineNone of the above