Whole Number Mental Add and Subtract Subtracting (vertical to 20) Slides 2-8 Teachers Use these experiences with whole numbers in any order to suit student needs. The experiences should be repeated many times across the year. Where possible, coordinate your language (and student language) to the actions occurring onscreen. Hints To use the pointer pen option to write numbers as provided by students: Click Slide Show. Right click mouse. Select Pen. To start at a specific slide: Click on Slide Show. Scroll to the Slide you want. Click From Current Slide.

18 -12 6 Ask: How many pink circles can you see? Click to show the number 18. Say: we are going to take some pink circles away. Click to show the -12. Ask: How many circles are we going to take away? Click to show 12 circles fading away. Count as they fade. Ask: How many pink circles are left/remain? Ask: What does 18-12 equal? Click to show the answer.

18 -13 5 As for slide 2.

17 -12 5 As for slide 2.

14 - 4 10 As for slide 2.

14 - 6 8 As for slide 2.

20 - 9 11 As for slide 2.

13 -12 1 As for slide 2.