Ratios are a foundation component of Algebra and are not completely understood due in part to the habit of teachers and educational material (including KA) of stating a ratio as ONE NUMBER.  For example, in KA Proportional Relationships where y/x=3/1 it is stated that is the same as y/x=3.  I think not, without repeated explanation that a rational number can always be written as number/1.  Accordingly, y/x = 3 means 3/1 and ONLY thus is a ratio equivalent to y/x=3/1.  You can't draw a line with a slope of 3.  It is 3/1.  A change in y of 3 over a change in x of 1.  So, let's make sure students understand Ratios by stating the Ratios when appropriate.