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
Chain Tasks
Person A: Write a number following directions
Person B: Draw a visual model of the number from A
Person C: Write the number representing model from B
Compare C and A
Note each step of this could be timed - visual models should convey accurate information but do not need to be perfect
Task A: Write down a number between 5 and 10
Chain Tasks
5 < n < 10
Task A: Write down a number between 5 and 10
Chain Tasks
Task B: Write down a number between 50 and 100
5 < n < 10
50 < n < 100
Task A: Write down a number between 5 and 10
Chain Tasks
Task B: Write down a number between 50 and 100
Task C: Write down a number between 1/2 and 1
5 < n < 10
50 < n < 100
1/2 < n < 1
Task A: Write down a number between 5 and 10
Chain Tasks
Task B: Write down a number between 50 and 100
Task C: Write down a number between 1/2 and 1
Task D: Write down a number between 1 1/2 and 1 3/4
5 < n < 10
50 < n < 100
1/2 < n < 1
1 1/2 < n < 1 3/4
Task A: Write down a number between 5 and 10
Chain Tasks
Task B: Write down a number between 50 and 100
Task C: Write down a number between 1/2 and 1
Task D: Write down a number between 1 1/2 and 1 3/4
5 < n < 10
50 < n < 100
1/2 < n < 1
1 1/2 < n < 1 3/4
Have students play match fraction, then try tasks C and D again