On a number line, we know that if we have two points, say -4 and 2, we know that the one on the right is bigger (2 > -4) and the one on the left is smaller (-4 < 2). Sometimes, however, we want to know which point is closer to or further from the origin (point 0). We use something called the absolute value...
Question
What's the absolute value of 2? -4? What's the symbology? Is |-4| > 2? What'sAnswer?
The symbology is two vertical lines with the number inside:.
Analysis
When we talk about the absolute value of a number, we're looking specifically at the distance between that point and 0. Because we're measuring a distance, the absolute value of a number is always positive.
As the Answer says, the way we indicate the absolute value of a number is using two vertical lines and put the number in between them (I've had teachers call them "goal posts").
Ok - so let's talk about taking the absolute value. Let's plot -4 and 2 on a number line and also plot the distances from those points to 0:
Notice how -4 is much farther away than 2. This means we'd expect
. And in fact it is.Let's go one step further - let's do this math:
Vocabulary used:
For more information check out these links (comment to add your favourite link):
https://www.mathplanet.com/education/pre-algebra/explore-and-understand-integers/absolute-value
Where might you have come from?
Fact-orials Index
Numbers:
Relations:
Graphing:
Where might we go?
Associated Operations:
A useful resource:
ReplyDeletehttps://www.mathplanet.com/education/pre-algebra/explore-and-understand-integers/absolute-value