Students are required to draw in arrows to show the parallel lines on three given shapes. They then draw in a right-angle symbol to show the perpendicular lines on three other given shapes.
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.