Once upon a time, there were three friends - Amy, Ben, and Claire. They found an old time machine that could take them to any year, but only if they solved a math problem using the four operations. One day, they decided to visit the year of the first manned moon landing. That s 1969! Claire exclaimed. They entered 1969 into the machine, but nothing happened. A voice from the machine said, To travel, subtract the current year from your desired year. It was the year 2022. Ben quickly subtracted 1969 from 2022 and entered the answer, 53. But, the machine asked for another operation. Now, divide your answer by the number of friends you are, it said. Claire divided 53 by 3 and entered 17.67. This time, the machine whirred to life, and the three friends were off on a fantastic journey through time, all thanks to the four operations!