In another part of the library, Sammy was sitting down with the Benson Brothers and teaching them how to do math. "Today, we will learn about addition and division." He said as hw twirled his air writer. "Can anyone tell me what the answer to this?" He asked as he wrote 100+50 on the board. Luke's hand instantly shot up. "Go ahead Luke," said Sammy.

"150," replied Luke.

"Good," said Sammy. Then he pointed at John and said, "John what is 150 divided by 5?"

John thought for a while before replying, "25?"

"No not quite. Here let me write it out for you," said Sammy. He then wrote the long division for 150/5 in the air in front of John. At the end he asked, "Now what is the correct answer?"

"30!' John yelled.

"Good, good," Sammy said as he uncovered his ears. "ha....Finally, Mark. Please add a 4 to 30."

What is Mark's answer?