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Name SKILL Date Class Are You Ready? Rounding and Estimation Rounding a number provides an approximate value of the number. Estimation is often used when the final result does not need to be an exact number. To round a number: Step 1: Find the place to which you are rounding. Step 2: Look at the digit immediately to the right of that place. Step 3: If this digit is greater than or equal to 5, round the digit in the rounding place up 1, If the digit is less than 5, the digit in the rounding place is unchanged. Step 4: If you are rounding to a decimal place or to the nearest whole number, drop the digits to the right of the rounding place. If you are rounding to tens, hundreds, or any larger place value, fill in zeros as needed. Example: Round 14.638 to the nearest tenth. Step 1: Step 2: Step 3: Step 4: Answer: The digit to be rounded is 6. 3 is to the right of 6. 3 < 5, so 6 is unchanged. Drop the digits 3 and 8. 14.6 Practice on Your Own Round each number to the indicated place value. 1. 146.3892; hundredth 2. 235.7; whole number 3. 47; tens 4. 15.275; tenth 5. 0.0048; thousandth 6. 3.99; tenth Estimate the sum or product by rounding each number to the indicated place value. 7. 76 + 148; tens 8. 9.46 x 18; tens 10. 412 + 709 + 99; hundreds 11. 6.62 x 1.89; tens 9. 10.2 •*• 1.975; ones 12. 780.5 ; 7.88; tens Check Estimate each number by rounding it to the indicated place value. 13. 0.0748; hundredth 14. 1324.8; whole number 15. 18.996; tenth Estimate the sum or product by rounding each number to the indicated place value. 16. 11.8 x 47; tens Copyright © by Holt. Rinehart and Winston. All rights reserved. 17. 862 + 59.4; hundreds 'Jfl UU 18. 9.2 -s- 2.866; ones Hnif Ronmotru null UGUIIIGU y Name Date Class Are You Ready? Simplify Fractions Definition: a fraction is in simplest form when the numerator and the denominator do not share any common factors, other than the factor of 1. An improper fraction should be written as a mixed number. To write a fraction in simplest form: Step 1: List all the factors of the numerator and the denominator. Step 2: Identify the greatest common factor (GCF). Step 3: Divide both the numerator and the denominator by the GCF. Example: Write in simplest form. Factors of 18: {1, 2, 3, 6, 9, 18} Factors of 45: (1, 3, 5, 9, 15, 45} GCF: 9 1 ft — Q P ft 1 7° ' „ = f 4b — 9 o O 7— written in simplest form is ~. 45 5 Practice on Your Own Identify the greatest common factor of the numerator and denominator of the fractions given. >. | | Factors of 36: 1. ~| Factors of 16: DO Factors of 24: Factors of 63: GCF: GCF: Write each fraction in simplest form. 3. 6 - D _ D R On 60 72 + D D 8. 24 49 56 121 66 5. 45 54 + 26 Check Identify the greatest common factor of the numerator and denominator of the fractions given. Q —t. UUInrF = 9. 12 10. I GCF = 11. I GCF = ' 180 \j Write each fraction in simplest form. 13. D 2i-D~D 16. 32 40 Copyright © by Holt, Rinehart and Winston. Al! rights reserved. 14. 15. 14 -f- 48+n 18 - D 18. Z2 17. 20 81 16 32 Holt Geometry Name Date Class Are You Ready? ^SKILL "' ' mim Multiply MU and Divide Fractions General Operation Reminders Multiplying Fractions Dividing Fractions Step 1: Multiply the numerators. Multiply the denominators. Step 2: Write the answer in simplest form. Divide by the greatest common factor if needed. Step 1: Find the reciprocal of the divisor (the second fraction) and rewrite the problem as a multiplication problem. Step 2: Multiply the numerators. Multiply the denominators. Step 3: Write the answer in simplest form. Divide by the greatest common factor if needed. Example 1: Multiply | x ~. 1 3 Example 2: Divide g ^ T- 2 5 6 ' 4 f\ 3_ 4~ X X O ^ = ~K GCF of 6 and 20 is 2.1 ^ 3 = 1 X 4 = A GCF of 4 and 18 is 2. ^ 20 = 2 0 - 2 = TO' The product is -r^r. 18 6 3 18-2 18 2 9' 2 The product is . Practice on Your Own Multiply or divide. Give your answer in simplest form. 2. 4 • 4 4 1 7X4 2 - 9 7- X 1 2 10 X 5 4. 3 . 2 8. 8 - Check Multiply or divide. Give your answer in simplest form. q lv 1 9- 9X 2 13.^x1 Copyright © by Holt, Rinehart and Winston. Al! rights reserved. , 2^3 ' • 5 ' 5 14. -6 19 _2_ j. JL 12' 11 ' 11 15. 106 x 2 16. 12+ Holt Geometry Name Date Class Are You Ready? SKILL Add and Subtract Fractions General Operation Reminders Adding and Subtracting Fractions Like Fractions (same denominators) Step 1: Add or subtract the numerators. Step 2: Write the sum or difference of the numerators over the denominator. Step 3: Write the answer in simplest form. Unlike Fractions (different denominators) Step 1: Find the least common denominator (LCD) and then rewrite each fraction so that its denominator is the LCD. Step 2: Follow the steps for adding or subtracting like fractions. 1 3 Example 2: Subtract 1p - T- Example 1: Add ~ + |. 1 , 5 _ 1+5 f-^ = | 8 + 8= (GCF of 6 and 8 isRewrite 2.) 1 as . The LCD of 2 and 4 is 4. — ~ ® """ ^ ___ 3 8~8-^2~4 • 3 4" Th 3v 2_6 2 2 4 6 4 3 4 3 4 The difference jis -3 4. Practice on Your Own Add or subtract. Give your answer in simplest form. 1 5 1. 5. 1] 3. 2 9 7 8 10 4 9 _ 3 7 3 7. 4 Check Add or subtract. Give your answer in simplest form. 9. 11 A 11 8~8 Copyright © by Holt, Rinehart and Winston. All rights reserved. 10 3 - 2 1Ul 9 9 14. 10 11 -3- + 1 "' 14 + 7 12. _ _ 12 4 1 4 3 ' 5 + T 5 + 10 3 5 108 Holt Geometry Name SKILL Date Class Are You Ready? Simplify Radical Expressions Definition: A radical expression is in simplest form when all of the following conditions are met. 1. The number, or expression, under the radical sign contains no perfect square factors (other than 1). 2. The expression under the radical sign does not contain a fraction. 3. If the expression is a fraction, the denominator does not contain a radical expression. How to Simplify Radical Expressions Look for perfect square factors and simplify these first. If the radical expression is preceded by a negative sign, then the answer is negative. If the expression is a product, simplify then multiply, or multiply then simplify, whichever is most convenient. If the expression is (or contains) a fraction, simplify then divide, or divide then simplify, whichever is most convenient. Example 1: Simplify Y81. Since 81 is a perfect square factor, simplify the expression to 9. Example 2: Simplify V25V16. Since both numbers are perfect squares, simplify then multiply: VS^SV^ • ~4 = 5 • 4 = 20 Example 3: Simplify - /_4__ V8T_= VsTl) = 9 -V81 = -V9" • 9 = _ 49 V2 • 2 2 -9 Practice on Your Own Simplify each expression. 81 1. V25 2. V9V36 3. 5. V'TOOV'4 6. 7. V169 V 121 4. -V8f ~V625 Check Simplify each expression. 9. Vl6 13. V2V50 Copyright © by Holt, Rinehart and Winston. All rights reserved. 10. V81V64 11. -V49 12. y 25_ 14. -Y144 15. -V9V4 16 -Vi 118 Holt Geometry Name Class Date Are You Ready? Solve One-Step Equations To solve a one-step equation, do the inverse of whatever operation is being done to the variable. Remember, because it is an equation, what is done to one side of the equation must also be done to the other side. Solve an addition equation using subtraction. Solve a subtraction equation using addition. x + 5 = 15 -5 -5 x =10 x - 8 = -3 +8 +8 x = 5 Solve a multiplication equation using division. Solve a division equation using multiplication. X 7x = 42 o 12 7x 42 7 7 x= 6 HO \C. ' X ~Tr) . ~ Q ~G HO l<£ x = -36 Practice on Your Own Solve. 1. m- 5 = 9 2• 5. 4y = -12 6. k+ 9 = -3 q9- ^ 4 = —- /-v — "~ —w — ^ D 3. 6x = 54 4. b + 15 = 25 7. p - 7 = -2 10. 5 +h= 16 11. -12x= -24 12. r - 2 = -9 13. 3x= 15 14. c- 11 = 1 15. d+ 9 = 5 16. 17. z - 2 = -17 18. 19. -10/7= 120 20. x + 99 - 100 Check Solve. Copyright © by Holt, Rinehart and Winston. All rights reserved. 148 Holt Geometry Name Date Class Are You Ready? Solve Multi-Step Equations To solve an equation, you need to isolate the variable on one side of the equals sign. Follow the order of operations in reverse to solve a multi-step equation. That is, add and subtract before you multiply or divide. Sometimes, you need to use the Distributive Property before you use inverse operations. Example: Solve 9x - 6 = 21. 9x - 6 = 21 +6 +6 9x = 27 9x 9 x 27 9 3 Add 6 to both sides. Divide both sides by 9. Practice on Your Own Solve. 1. 3x- 2 = 10 2. 7m + 3 = 45 3. 12 + , p _ 3« = 5. -12 - 9y = -20 6. 26 = 5c - 4 7. 3(|+ 2) = -9 8. 5(2n- 1) = -5 9. 2(h + 3) + 5/? = -3 4. 4 = 17 Check Solve. 10. 8x+ 1 = 17 11. -3 + 13. 18 = |+15 14. -3(x + 4) = -5 Copyright © by Holt. Rinehart and Winston. Al! rights reserved. = -7 150 12. -12 + 6fif = 14 15. 5(z- 2) + 3z= 14 Holt Geometry Name SKILL Date Class Are You Ready? LLII Solve Equations with Variables on Both Sides To solve an equation with variables on both sides: Step 1 : Move all the variable expressions to one side of the equals sign by adding or subtracting. Step 2: Isolate the variable by adding or subtracting any constants and then multiplying or dividing by any coefficients. Example: Solve 7x - 12 = 3x + 8. Step 1: Subtract Sxfrom both sides. 7x - 12 = 3x + 8 3x 3x ~4x- 12 =~ 8 Step 2: Add 12 to both sides, then divide both sides by 4. 4x - 12 = +12 8 +12 4x 4 x- 20 4 5 Practice on Your Own Solve. 1. 3y + 5 = 9 y - 1 3 2. 4 + 11m = 7 m - 1 3. 9 x + 1 5 - 7 4. -1 - 3f = 9 - 8f 5. x - 11 = 7x - 8 6. 3b + 5 = -2b + 5 7. -k - 7 = -5/c - 6 8. 16 - 3x = 5x - 8 9. -6a - 4 = -7a - 5 Check Solve. 10. 15x+ 1 = 13x+ 17 11.9-4f=2f-1 13. p + 1 3 = 5 p + 5 14. -56+ 11 = 7 - 6 b Copyright © by Holt. Rinehart and Winston. All rights reserved. "1 *1? ' »"• 12. 6 y - 5 = 7 y + 1 15. - x - 8 = -5x - 10 Hfllt Mul1 Name SKILL Date Class Are You Ready? Solve Equations with Fractions You solve multi-step equations with fractions just like you solve multi-step equations with integers. Step 1: Use inverse operations to undo any addition or subtraction. Step 2: When the coefficient of the variable is a fraction, multiply each side of the equation by the reciprocal of the fraction and then simplify. If the coefficient is not a fraction, but there are other fractions in the equation, multiply by the reciprocal of the coefficient rather than dividing. Example: Solve x - 12 = 8. |x - 1 2 + 12 = 8 + 12 Add 12 to both sides. fx = 2 0 5 .4 2 5 4 5X ~ ^ 4 # /r Multiply by the reciprocal. Simplify. Y — .A Practice on Your Own Solve. 1. fx + 5 = 17 2. A 9y + 4. IX + _ 5. x 7 7. - 1_ 5 - 7 -7 3 — 1 9 3 8 8 8. 6x == 3x 25 3.4y- = " 4 9. 4y = 9y - § Check Solve. 10. |x+ 11 = 21 10 5 TT = TT Copyright © by Holt, Rinehart and Winston. All rights reserved. 11.y-8=-7 1 -3 2 ~2 154 12. 5x- 10 15. 8x = 5x Holt Geometry