What are we going to do? CFU Students, you already know how to determine the opposite of a number. Now, we will use the opposite of numbers to add and subtract numbers. Make Connection We will add and subtract on a number line. Learning Objective Activate Prior Knowledge 7.NS.1 Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram. 8.G.1 Verify experimentally the properties translations. We will translate geometric figures on a coordinate plane. Adding and subtracting on a number line will help you understand positive and negative numbers in the real world. Morning Temperature: -5 F Afternoon Temperature: 10°F Temperature Change: 15°F
Addition means to put together. On a number line, the sum of two numbers is the location after moving from the first addend a distance of the second addend. Subtraction means to add the opposite. Explain how the number line below shows the addition problem 2 + (-3). Which is equivalent to the subtraction problem 7 (-2) ? How do you know? A 7 + (-2) B 7 + (2) In your own words what does subtraction mean? Subtraction means _________. CFU Activating Prior Knowledge (-3) (-5) -5 3 53 (5) 5 -1 (-5) Addition distance a ( b) direction
Rewrite subtraction to add the opposite, if necessary. Locate the first addend on the number line. Move the distance of the second addend. Interpret 1 the answer. “The sum/difference of __ and __ is __.” Add and subtract on a number line explain (synonym) Vocabulary How did I/you rewrite subtraction? How did I/you move the distance of the second addend? CFU 1 3 Activating Prior Knowledge Addition means to put together. Subtraction means to add the opposite (-7) (-3) Addition distance a ( b) direction
5. Jesse owes his brother $7. He gets $15 for allowance this week. How much money will he have after he pays his brother back? _____________________________________________________________________________ 6. Courtney’s class is playing a math game. She starts her turn with -3 points. This turn, she loses 4 points. How many points does Courtney have now? ______________________________________________________________________________ Skill Development/Guided Practice (continued) How did I/you determine what the question is asking? How did I/you determine the math concept required? How did I/you determine the relevant information? How did I/you solve and interpret the problem? How did I/you check the reasonableness of the answer? CFU Jesse will have $8 after he pays his brother back. -3 4 -3 (-4) Courtney now has -7 points.
x-axis y-axis The coordinate plane is a flat surface made by the intersection 2 of two perpendicular 3 number lines. An ordered pair describes 4 the location of a point on the coordinate plane using x- and y-coordinates. On your whiteboard, write an example of an ordered pair. Which number is the x- coordinate? Which is the y- coordinate? How do you know? Which of the following is the ordered pair that identifies the location of the point T? A T B (7, 9) In your own words, what is an ordered pair? “An ordered pair is ______.” CFU Ordered Pairs on the Coordinate Plane 2 crossing (synonym) 3 crossing at a 90 degree angle 4 shows (synonym) Vocabulary Concept Development “X is the point’s distance along the x-axis.” “Y is the point’s distance along the y-axis.” – the horizontal number line. – the vertical number line. The origin is where the x-axis and y-axis intersect. (4, 5) 5 4 “Y is the point’s distance along the y-axis.” “X is the point’s distance along the x-axis.” T Animated Ordered Pair (2, 3) x and y
x-axis y-axis The coordinate plane is a flat surface made by the intersection 2 of two perpendicular 3 number lines. An ordered pair describes 4 the location of a point on the coordinate plane using x- and y-coordinates. How do you translate a geometric figure? In your own words, what does it mean to translate an ordered pair? “Translating an ordered pair means ______________.” CFU Translating 5 Ordered Pairs on the Coordinate Plane 2 crossing (synonym) 3 crossing at a 90 degree angle 4 shows (synonym) 5 moving in one or more directions (synonym) Vocabulary Concept Development o Locate the point (4,4). o In order to move from the (4,4) to Point T’s location, how far does the point need to move horizontally? How far does it move vertically? – the horizontal number line. – the vertical number line. The origin is where the x-axis and y-axis intersect. (4, 4) 4 4 T Ordered Pair (2, 3) x and y (+4 ) RIGHT (+5 ) UP
How do you translate a geometric figure? In your own words, how do you determine which direction to move on x axis? On y axis? CFU Translating Ordered Pairs on the Coordinate Plane X moves left (if negative) or right (if positive) Y moves down (if negative) or up (if positive) Concept Development Ordered Pair (2, 3) x and y (-6) = LEFT (+2) = UP
Translating Ordered Pairs on the Coordinate Plane X moves left (if negative) or right (if positive) Y moves down (if negative) or up (if positive) Guided Practice Ordered Pair (2, 3) x and y
Translating Ordered Pairs on the Coordinate Plane X moves left (if negative) or right (if positive) Y moves down (if negative) or up (if positive) Skill Closure Ordered Pair (2, 3) x and y