In the last Mathematical Problem Solving class this week we studied even and odd numbers, les entiers pairs et impairs. We used some simple algebra to prove that the sum of two even numbers is even, the sum of two odd numbers is even, and an even number plus an odd number is odd. We also explored the even/odd pattern in Pascal’s triangle. The students asked about numbers that are evenly divisible by 3, or have a remainder of 1, or of 2. We decided to call those numbers “threeven”, “throdd”, and “negathrodd”, respectively. The name of the last comes from the observation one of the students made, that having a remainder of 2 is the same as having a remainder of -1.
Attached is the worksheet.