(7) Lesson 4.3 - Add and Subtract Like Fractions
- 1. Course 2, Lesson 4-3 Replace each with <, >, or = to make a true statement. Use a number line if necessary. 1. 2. 3. 4. List each set of numbers in order from least to greatest. 5. 0.75, , 65% 6. −3.55, −3.46, 7. In one litter of kittens, 2 out of 5 were male. In a second litter, 4 out of 6 were male. Which litter had the greater percent of male kittens? 4 7 7 16 2 3 3 13 4 1 13 4 1 5 6 2 16 2 3 32 8 27 3 50
- 2. Course 2, Lesson 4-3 ANSWERS 1. > 2. < 3. > 4. = 5. 65%, , 0.75 6. –3.55, , –3.46 7. Litter 2 2 3 27 3 50
- 3. WHAT happens when you add, subtract, multiply, and divide fractions? The Number System Course 2, Lesson 4-3
- 4. Course 2, Lesson 4-3 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. The Number System • 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. • 7.NS.1c Understand subtraction of rational numbers as adding the additive inverse, p – q = p + (–q). Show that the distance between two rational numbers on the number line is the absolute value of their difference, and apply this principle in real-world contexts. • 7.NS.1d Apply properties of operations as strategies to add and subtract rational numbers. • 7.NS.3 Solve real-world and mathematical problems involving the four operations with rational numbers.
- 5. The Number System • 7.EE.3 Solve multi-step real-life and mathematical problems posed with positive and negative rational numbers in any form (whole numbers, fractions, and decimals), using tools strategically. Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate; and assess the reasonableness of answers using mental computation and estimation strategies. Mathematical Practices 1 Make sense of problems and persevere in solving them. 3 Construct viable arguments and critique the reasoning of others. 4 Model with mathematics. 7 Look for and make use of structure. Course 2, Lesson 4-3 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.
- 6. • To add like fractions • To subtract like fractions Course 2, Lesson 4-3 The Number System
- 7. Course 2, Lesson 4-3 The Number System • like fractions 11 4and 12 12 2 1and 3 3
- 8. Course 2, Lesson 4-3 The Number System Words To add or subtract like fractions, add or subtract the numerators and write the result over the denominator. Examples Numbers Algebra 5 2 5 2 7 or 10 10 10 10 11 4 11 4 7 or 12 12 12 12 , where 0 a b a b c c c c , where 0 a b a b c c c c
- 9. 1 Need Another Example? 2 3 Step-by-Step Example 1. Add + . Write in simplest form. Add the numerators. Simplify.
- 10. Answer Need Another Example? 1 Find + . Write in simplest form.
- 11. 1 Need Another Example? 2 3 Step-by-Step Example 2. Add – + – . Write in simplest form. Add the numerators. Use the rules for adding integers.
- 12. Answer Need Another Example? Find – + – . Write in simplest form.
- 13. 1 Need Another Example? 2 3 4 Step-by-Step Example 3. Commutative Property of Addition Associative Property of Addition Simplify. So, Sofia and Jack ate 1 pizzas altogether. Sofia ate of a cheese pizza. Jack ate of a cheese pizza and of a pepperoni pizza. How much pizza did Sofia and Jack eat altogether?
- 14. Answer Need Another Example? On Monday, Kieffer worked on a project for of an hour. On Tuesday, he worked on it for of an hour and on Wednesday he worked for of an hour. How much time did he spend working on his project?
- 15. 1 Need Another Example? 2 3 Step-by-Step Example 4. Find – – . Add the numerators. = – or –1 Simplify.
- 16. Answer Need Another Example? Find – – . Write in simplest form.
- 17. 1 Need Another Example? 2 3 Step-by-Step Example 5. Find – . Simplify. Subtract the numerators. = – or – =
- 18. Answer Need Another Example? Find – . Write in simplest form.
- 19. 1 Need Another Example? 2 3 Step-by-Step Example 6. About of the population of the United States lives in Florida. Another lives in Ohio. About what fraction more of the U.S. population lives in Florida than in Ohio? Simplify. Subtract the numerators. = or = About more of the U.S. population lives in Florida than in Ohio.
- 20. Answer Need Another Example? A picture mounted on art board is inch thick. The frame for the picture is inch thick. How much thicker than the picture is the frame?
- 21. How did what you learned today help you answer the WHAT happens when you add, subtract, multiply, and divide fractions? Course 2, Lesson 4-3 The Number System
- 22. How did what you learned today help you answer the WHAT happens when you add, subtract, multiply, and divide fractions? Course 2, Lesson 4-3 The Number System Sample answer: • When you add or subtract like fractions, add or subtract the numerators. Then, write the result over the denominator.
- 23. The next lesson is about adding and subtracting fractions with unlike denominators. How do you think what you learned in this lesson will connect with the next lesson? Course 2, Lesson 4-3 Ratios and Proportional RelationshipsThe Number System