Applications of signed numbers

1. AIM: How are signed numbers applied ? OBJECTIVE: S.W.B.A.T. think of signed numbers in real world contexts Homework: #4 - Basics of Algebra September 26, 2007 DO NOW Have you ever seen negative numbers used in real-life? Where have you seen them used ? Test Friday!!!!!

3. Applications of signed numbers – Example 1 1. A proton has a charge of positive one. An electron has a charge of negative one. Find the total charge of an ion with 12 protons and 15 electrons. Total means add Electrons - negative Protons - positive

4. Applications of signed numbers – Example 2 If the temperature goes up by 60 degrees then down by 75 degrees and then up by 10 degrees what is the total change in temperature? Express your answer as a positive or negative number. If the temperature decreases from start to finish our answer should be negative . If the temperature increases our answer should be positive . +60 -75 +10

5. Applications of signed numbers – Example 3 3. The sea is 1200 feet deep. A submarine is at -500 feet, or 500 feet below sea level. The ship is then directed to descend 650 feet, then to ascend 350 feet, then to descend 340 feet, then to ascend 150 feet. What altitude was the submarine at after the final ascent? -500 – 650 + 350 – 340 + 150

6. Groupwork 4, 6a, 7 Extra Credit: 5