Tag Archives: ruler

Let’s actually use the number line

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.

numberline locating fractions

numberline multiply 1

numberline multiply frac

numberline frac division



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Filed under arithmetic, fractions, geometry

In the future (tomorrow?)

“Mommy, teacher says we all have to get the new eyepad”.

“Why? What’s wrong with the one you’ve got?”.

“She says it’s much better, the screen goes right to the edge, and we can use the Ruler App to measure things”.

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Filed under geometry, humor