Students estimate a division problem, share their methods, discuss the nice numbers and factors method, and then do more problems using nice numbers and factors.
Students discuss making an interval estimate in multiplication problems (i.e., getting a lower and an upper limit for the actual answer using the front-end and rounding-up estimation methods). They then use this method on two problems.
Students estimate an addition problem, share their methods, discuss grouping nice numbers, and then do a problem using this method, then design a question showing how it uses the method.
In this practical task, students estimate, and then measure, the weight of two objects using a number of multi-link cubes, a balance scale and weights.
This practical task requires students to construct a one metre newspaper roll, use it to estimate the dimensions of a room, then calculate the volume of that room.
Students write down an explanation of how the front-end estimation strategy works in addition problems to give information on their understanding of the strategy.
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.