Let’s have a number line. We can count up or down by moving to the right or the left, or actually up or down if the number line is drawn vertically.

But what else ?????

The following pictures show how points on the number line which represent fractions can be found exactly by simple geometrical construction, and then how results of multiplication and division of fractions can be found exactly as points on the number line (sorry, the numerical values are however not found).

This arose from a statement in the CCSS math document that the fraction 1/6 could be represented by a point one sixth of the way from zero to one, BUT NOWHERE DOES IT SAY HOW TO FIND THAT POINT.

Filed under arithmetic, fractions, geometry

Tagged as compass, construction, divide, division, math, multiplication, multiply, ruler, similar triangles, simple