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Lesson 8: Missing Addends. Ms. Jamie Scordino 3 rd Grade Math. Review: Addition Problems. Santana picked 14 apples. Her friend, Wilson brought her 16 more. Altogether, how many apples does she have now?. Review: Addition Problems.
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Lesson 8: Missing Addends Ms. Jamie Scordino 3rd Grade Math
Review: Addition Problems Santana picked 14 apples. Her friend, Wilson brought her 16 more. Altogether, how many apples does she have now?
Review: Addition Problems Santana picked 14 apples. Her friend, Wilson brought her 16 more. Altogether, how many apples does she have now? 14 +16 30 1
Vocabulary Variable- a quantity that can assume any set of numbers Ex. letters (like a, x, y, z, n),box ( ) 4 + X Here x can be ANY number
Vocabulary Equation- a mathematical statement that two expressions are equal. When we have an equation, we can solve for a variable. 4 + X = 10 Both sides equal 10. We can solve for X.
Solving Equations First way: Sometimes we just know the answer 4 + X = 10 We know X must be 6 to make this true. 4 + 6 = 10 This says 4 + some number is equal to10.
Solving Equations We can take away the number on both sides to be left with our variable. NEED TO KNOW: What we do to one side we have to do to the other side! Second way: 4 + X = 10 -4- 4 0 + X = 6 So X = 6
Problem #1 If we do something to one side, we MUST do the same thing to the other side. Need to take away 5 to be left with the variable. 5 + n = 16 -5-5 0 + n =11 n = 11
Your Turn 8 + h = 19
Solution Great Job! • + h = 19 - 8- 8 0 + h = 11 h = 11
Problem #2 (Tougher) If we do something to one side, we MUST do the same thing to the other side. 6 Need to take away the 39 to be left with the variable. 39 + s = 76 -39-39 0 + s =37 s = 37
Your Turn 74 + z = 92
Solution Great Job! 74 + z = 92 -74-74 0 + z = 18 z = 18 8
Problem #3 (Toughest) 10 + w + 5 = 20 add 10 + 5 Now: 15 + w = 20 -15 -15 0 + w = 5 w = 5 1
Problem #4 (Toughest) 8 + t + 4 = 25 add 8 + 4 Now: 12 + t = 25 -12-12 0 + t = 13 t = 13
Your Turn 4 + u + 1 = 12
Solution Great Job! 4 + u + 1 = 12 5 + u = 12 -5- 5 0 + u = 7 u = 7 0
Word Problem #1 Chou had five pineapples. Her mother brought home some more. Now, she has 18 pineapples. How many pineapples did her mom bring home? Number Sentence: 5 + p = 18 - 5 - 5 0 + p = 13 p = 13
Word Problem #2 Phoenix had seven pencils. He found some more on the ground. Now, he has 14 pencils. How many pencils did he find on the ground? Number Sentence: 7 + p = 14 - 7 - 7 0 + p = 6 p = 6
Your Turn Thank you for a great lesson!