Algebra Comp Edge 5 02 Use algebraic expressions

Algebra Comp. Edge 5. 02: Use algebraic expressions, patterns, and one-step equations and inequalities to solve problems. WOES Fifth Grade 2011 -12

Writing Equations • An equation is a mathematical sentence that has a variable and an equal sign. A variable is a letter of the alphabet that is used to replace a missing number. • Examples • A number decreased by 2 is equal to nine. x– 2=9 • A number increased by 11 is equal to sixteen. y + 11 = 16

Write an equation for each sentence. 1. A # increased by eleven is equal to 40 2. A # decreased by five is equal to nineteen 3. Three times a # is = to 12 4. Nine · a # is = to forty-five 5. A # ÷ by seven is = to 14 6. A # + six is equal to eighteen 7. A # less than five is equal to ten 8. A # divided by six is = to 12 9. A # less than three is equal to fourteen 10. A # decreased by six is = to 24 11. seven times a # is = to 63 12. A number increased by 20 is = to 72 13. A number less nine is equal to thirteen 14. Eight times a number is equal to 64 15. A # plus fifteen is equal to eighty

One-Step Equations: Addition In solving any equation, the variable ( the letter) needs (wants) to be alone. Addition: • To solve addition equations, you subtract ( the opposite of adding). • Example: y wants to be alone. Get rid of the 14 by subtracting it. When y + 14 = 24 you subtract 14 from one side of the equation, you must also - 14 -14 subtract 14 from the other side. y = 11

Practice: Addition 1. x + 4 = 8 3. t + 3 = 18 5. 2 + c = 20 7. f + 14 = 25 9. n + 2 = 10 11. b + 1 = 7 13. g + 18 = 100 15. h + 19 = 110 17. s + 193 = 300 2. y + 17 = 21 4. 4 + y = 11 6. d + 3 = 8 8. d + 2 = 117 10. s + 3 = 21 12. 5 + c = 11 14. 25 + c = 243 16. 213 + k = 541 18. 24 + t = 188

One-Step Equations: Subtraction Again, the letter (variable) wants to be alone. Subtraction: • To solve subtraction equations, you add ( the opposite of addition). • Example: X wants to be alone. Get rid of the x – 25 = 100 25 by adding it. When you add 25 to one side of the equation, you must + 25 also add 25 to the other side. x = 125

Practice: Subtraction 1. D – 6 = 21 3. T – 3 = 0 5. 16 = c – 24 7. 18 = n – 1. 5 9. 27 = y – 14 11. S – 104 = 15 13. 6 = s – 3. 4 15. 245 = x – 148 17. 100 = c – 42 2. 34 = n – 18 4. k – 18 = 5 6. 0 = d – 24 8. a – 41 = 136 10. 5 = r – 5 12. 217 = y – 41 14. y – 143 = 873 16. b – 124 = 871 18. 145. 6 = y – 1. 45

One-Step Equations: Multiplication To solve multiplication equations, you divide ( the opposite of multiplying). Example: x wants to be alone. 6 x = 24 Divide both sides by the 6. 6 x = 24 6 6 x = 4

Practice: Multiplication 1. 100 = 50 c 3. 240 = 8 n 5. 7 y = 91 7. 9 d = 63 9. 5 b = 45 11. 2 r = 26 13. 48 = 6 s 15. 195 = 15 z 17. 120 = 3 g 2. 15 e = 150 4. 60 = 5 x 6. 100 d = 1, 400 8. 300 = 6 g 10. 4 n = 20 12. 25 s = 75 14. 540 = 9 y 16. 45 = 15 y 18. 17 x = 3, 944

Writing Inequalities An inequality is a mathematical sentence that contains a variable and uses one of the following inequality signs: < , > , < , >. Examples: a number is less than 45 n < 45 a number is greater than or equal to 12 Quantiles: y > 12 http: //virtualnerd. com/embed/vid. php? id=Alg 1_2 b&size=medium

1. 2. 3. 4. 5. 6. 7. 8. 9. Write an inequality for each statement. Some # y increased by 7 is less than 12 Some # z decreased by 5 is greater than 10 Seven times a # is less than 40 A # divided by 3 is greater than 14 A # t minus 11 is less than 21 6 times z plus 14 is less than or equal to 100 Some # divided by 6 is greater than 24 A # y decreased by 17 is greater than or = to 40 Nine times g is less than 20

10. Some # increased by 21 is less than or equal to 112 11. A number d divided by 21 is greater than 7 12. some # plus 21 is less than 45 13. A # c divided by 14 is less than or equal to 75 14. twelve times a # is greater than 50 15. A number decreased by 2 is less than 7 Keep Up The Great Effort

Web Resources: Quantiles. com: http: //qta. quantiles. com/m/resources/downloads/Quantile. Resource 4200 9. pdf ixl. com • Q. 1 Simplify expressions using order of operations and parentheses • Q. 2 Write variable expressions • Q. 3 Evaluate variable expressions • Q. 4 Write equations to represent word problems • Q. 5 Solve equations I • Q. 6 Solve equations II Aaamath. com http: //www. aaaknow. com/equ. htm Coolschools. com http: //softschools. com/grades/5 thgrade. jsp