Kelsey loves to count. One day Ms Martin put a pile of cubes on Kelsey’s desk. Kelsey began to count the cubes. She told Ms Martin the following facts about the cubes:
When I count the cubes by two I have one left over.
When I count the cubes by three I have one left over.
When I count the cubes by four I have one left over.
When I count by seven I have none left over.