I’m delighted to have released iPad app I See Addition and Subtraction with Alan Peat ltd. The app allows teachers to make a range of high quality visual images with a few clicks. Below are three of my favourite alternative uses for the app.
1. What’s the whole? Estimating with the Singapore Bar
The sections of the Singapore Bar are proportionately spaced. If, therefore, I show one of the parts the size of the whole can be estimated with spatial reasoning:
By clicking on the number boxes, the numbers are revealed:
Alternatively, the whole can be shown and the parts (2 and 4) then revealed:
2. Missing values on 100-square
By clicking on the boxes on the 100-square, the numbers are hidden. Then, with a quick edit on Explain Everything I have made this image – children work out the value of the red boxes:
3. Reasoning with the 100-square
Hide the numbers on the 100-square as below. How many numbers are hidden? And how many different ways can you work it out?
Do children add four equally sized blocks? Two pairs of different sized blocks? Or subtract the number of boxes in the middle from the whole?
I’d love to see how you’ve used I See Addition and Subtraction!