If this book appeals to you then you should see 3 brown 1 blue's videos on YouTube. The way they show the squares with the 'little bits' added in Calculus Made

If this book appeals to you then you should see 3 brown 1 blue's videos on YouTube. The way they show the squares with the 'little bits' added in Calculus Made Easy is essentially repeated in 3 brown 1 blue, with graphics.