This unit explores the idea that carrying out certain calculations mentally (eg doubling, halving, multiplying and dividing by ten) is relatively easy and that these operations can then be combined to perform other calculations such as multiplying and dividing by 4, 8, 5, 20 etc.
We begin with three different visualisations (double number bond diagram, place value chart and function machines).
We then explore the effect of combining operations.
Once the concept is understood, we consolidate with a talking game and pair challenge game.
Important Note: Teacher or parent guidance for using these slides can be found in the speaker notes section, which can be found by clicking on the three dots which appear when you click or mouseover the bottom left of a slide.