Student solve addition problems where the missing value is located in different positions. This may mean that students transform the problem into a subtraction one. Students reflect on the easiest and hardest problems, and explain their choice.
Students discuss making an initial estimate in addition problems using the front-end method followed by compensation to get a more accurate estimate. They then use this method on two addition problems.
This practical task requires students to collect data about gender and left- or right- handedness from a group or class, present their data in a 2 × 2 array, and make a statement based on their findings.