Absolute Value & Magnitude

How the lesson starts: Absolute Value & Magnitude

Marina and Finn
Diver Marina swims down to −18 m to visit a friendly octopus. Her pal Finn floats his balloon up to 18 m. Who is farther from sea level? It's a tie! Both are 18 m away. That 'how far from zero' idea has a name: absolute value.
Distance from zero
Absolute value is a number's distance from 0. −7 is 7 steps from 0, and so is 7. So the absolute value of −7 is 7, and the absolute value of 7 is 7 too. We write it with two bars: |−7| = 7.
Find the distance
What is the absolute value of −12? Count how far −12 is from 0: 12 steps. So |−12| = 12. Now go the other way. Where is a point 4 units from 0? Count 4 steps from 0. You can land on 4, or on −4 on the other side.