simplest forms of ratios

 the powerpoint is here

ratio and rectangles

'lengths and areas are the most natural means to visualise magnitudes with respect to teaching ratio'

Hans Freudenthal

linking ratio to enlargement, as Freudenthal advocates

the powerpoint is here

I'm not sure whether this is better with all the dots or not...

one with, one without

what is the ratio of one of the stripes in simplest form?

in the form 1 : n ?

equivalent ratios

scaling a ratio
forming equivalent pairs for 3 : 5
the powerpoint is here

exploring the notion of equivalent ratios

 rectangles in proportion

 adopting different units

 a window on a multiplication grid

right angled triangles underneath a line