#### Transcript of opposite quantities that combine to make zero

**quantities that combine to make zero**

Temperatures on a thermometer

Temperatures above zero degrees are positive (+10) and temperatures below zero degrees are negative (-10).

Sports Scores

If your favorite football team gained 4 yards during the big game, it could be represented by +4. Should your team lose 4 yards, it could be represented by -4.

Weight gain and loss

Sam gained 8 pounds while on a Caribbean cruise (+8), but lost 8 pounds (-8) after he returned home.

Geography

A location in death valley has an elevation of -282 feet (which is below sea level), while a location near Coffin Peak has an elevation of +282 feet (which is above sea level).

Altitude

An airplane leaves the airport and climbs to an altitude (height) of 2500 feet (+2500). To land, the plane must lose 2500 feet of altitude (-2500).

Opposites

Positive and negative numbers can represent or describe many different situations which demonstrate the concept of opposites!

Write this

John earned $5.oo doing his chores on Sunday. On Monday, John bought a video game that cost $5.00. How much does John have left?

Why?

The amount John earned is a quantity and the amount John spent is a quantity. Why do they combine to make zero?

What about this...

John earned $5.00 doing his chores on Sunday. On Monday, he bought a candy bar that cost $1.50 and a magazine that cost $3.50. How much money does John have left?

Can you make a math sentence to represent this? Are these opposite quantities?

Your turn: with your partner, create two written scenarios where quantities combine to make zero.

1) a scenario where the quantities are opposite quantities.

2) A different scenario where quantities are not opposite quantities

Additive inverse

Additive inverses are numbers and their opposites that have a sum of zero.

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