5th_NS_1.3_add_and_subtract_integers (1).ppt
- 1. Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3
- 2. What do we already know? • Positive integers are on the right side of zero. 4 • Negative integers are on the left side of zero. -4 • This means that they are opposites. -3 + 3 = 0 Positive Negative
- 3. 5 + -2 = 3 5 -2 You know how to plot an expression on the number line and find the sum. Step 1: Plot the first integer on the number line. Step 2: Plot the second integer on the number line beginning where the last number left off.
- 4. You know how to plot an expression on the number line and find the difference. 5 + -2= 5 -2 3 Step 1: Plot the first integer on the number line. Step 2: Plot the second integer on the number line beginning where the last number left off.
- 5. You know how to plot an expression on the number line and find each sum. -3 + -1 = - 4 -1 -3 Step 1: Plot the first integer on the number line. Step 2: Plot the second integer on the number line beginning where the last number left off.
- 6. You already learned that subtracting a negative integer gives the same solution as adding its opposite.
- 7. Vocabulary • Define integers: a positive or negative number. • Define a positive integer: whole numbers to the left of zero. • Define a negative integer: whole numbers to the right of zero. positive negative
- 8. Vocabulary Define absolute value: the distance from zero. Plot each of the integers below on a number line and then tell the absolute value of each. -1 2 -5 (1) (2) (5) -1 2 -5
- 9. You already learned that subtracting a negative integer gives the same solution as adding its opposite. To help predict whether the sum of two integers will be positive or negative, you can use these rules.
- 10. 1st Variation Is the sum of 2 and 7 positive or negative? Rule: The sum of two positive integers is positive. 2+7= Solution: The sum of 2 and 7 is positive. 2 7 9 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off.
- 11. 2nd Variation Is the sum of -2 and -7 positive or negative? Rule: the sum of two negative integers is negative. -2 + -7= Solution: The sum of -2 and -7 is negative. -2 -7 -9 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off.
- 12. 3rd Variation Is the sum of -2 and 7 positive or negative? Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value. -2 + 7= Solution: The sum of -2 and 7 is positive. -2 7 5 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off.
- 13. Why is this important? If the temperature was 10 ｰ F at lunch time and dropped to - 5 ｰ F in the evening. What is the difference between these temperatures? 10 - -5= 15 degrees Mauricio were at the corner store. Mauricio forgot his money and needs $10 to pay for his treats. If Omar let Mauricio borrow $10, Mauricio now has $10. - $10 + $10 = 0
- 14. Guided Practice - I Do It Rule: The sum of two positive integers is positive. 1 + 4= 1 4 5 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The sum of 1 and 4 is positive.
- 15. Guided Practice - We Do It Rule: The sum of two positive integers is positive. 5 + 3= 5 3 8 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The sum of 5 and 3 is positive.
- 16. Guided Practice - You Do It Rule: The sum of two positive integers is positive. 7 + 3= 7 3 10 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The sum of 7 and 3 is positive.
- 17. Guided Practice - I Do It Rule: the sum of two negative integers is negative. -2 + -3= -2 -3 -5 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The sum of -2 and -3 is negative.
- 18. Guided Practice - We Do It Rule: the sum of two negative integers is negative. -1 + -4= -1 -4 -5 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The sum of -1 and -4 is negative.
- 19. Guided Practice - You Do It Rule: the sum of two negative integers is negative. -4 + -6= -4 -6 -10 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The sum of -6 and- 4 is negative.
- 20. Guided Practice - I Do It Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value. 4 - -2= 4 + 2= 6 4 2 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The difference of 4 and -2 is positive.
- 21. Guided Practice - We Do It Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value. 4 - -6= 4 + 6= 4 6 10 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The difference of 4 and -6 is positive.
- 22. Guided Practice - You Do It Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value. 3 - -7= 3 + 7 = 3 7 Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off. Solution: The difference of 3 and -7 is positive. 10
- 23. Closure • What is a whole number to the right of zero? • It is a positive integer. • What is a whole number to the left of zero? • It is a negative integer • What is the distance from zero? • It is the absolute value. QuickTime™ and a decompressor are needed to see this picture. Negative Positive
- 24. Closure Decide if the sum or difference is positive or negative. Explain how you decided. Solve the expression. -10 + -6 = 8 - -6= Share with your partner one thing that you learned today.
- 25. Step 1: Change the expression to an addition by using the absolute value. Step 2: Plot the first integer on the number line. Step 3: Plot the second integer on the number line beginning where the last number left off.
Editor's Notes
- #1: What are we going to do today? What are we going to (skill)? What are we going to do with (concept)?
- #2: Connect to Learning Objective Show me a positive number on the white board. Negative number. Write two integers that are opposite that equal to zero. Tell your partner why is the sum of the two integers zero.
- #3: RAJ What is an integer? Pair share Pull sticks Which example is positive integer? Choice A -4 Choice B 9 Tell your partner how do you know which one is a positive integer? Use a sentence frame 的 knew that _ is a positive integer because_� Repeat for negative integer.
- #13: Does anyone else have any other reason as to why it is important? Which reason is most important to you? Why? You can give me my reason or your reason.
- #15: Do I move left or right from 0 for the first integer? Which way do I move to subtract the second integer?
- #21: Are both sides the same? What is the sign of the integer with the greatest value?