Big Ideas: Grade 4 

Problems (tasks which students do not already have the tools to solve) precede teaching of the focal mathematics necessitated by the problem.

That is, the major point of a problem is to raise questions that can be answered and encourage students to use their intuition to address the questions before learning new mathematical ideas (Deslauriers et al., 2019).

From the 2023 CA Framework

Magic 495

1. Pick any 3-digit number (with no repeating digits no zeros).

                 372 OK, 333 NOT OK, 304 NOT OK

2. Make the biggest number possible with these digits

3. Make the smallest number possible with these digits

4. Subtract the small number from the big number

How many people have 495? If you don't repeat steps 2, 3, 4. (again)

What do you notice? What do you wonder?

Why? Can you prove it or find a counterexample?