YOU WILL NEED PAPER AND PENCIL Lesson Quizzes with clickers. Warm Up -- get your clickers please AND YOU WILL NEED PAPER AND PENCIL Problem of the Day – a brainteaser Lesson Presentation Lesson Quizzes with clickers.

Add or subtract, answer in simplest form. Warm Up Add or subtract, answer in simplest form. 1. 2. 3. 4. 9 11 __ 5 8 11 20 __ 2 9 __ 6 5

Problem of the Day Lydia works at a dog kennel. She uses 5 pounds of dog food to feed 3 dogs for 4 days. At the same feeding rate, how many pounds of dog food will Lydia need to feed 12 dogs for 1 week?

Answer: 35 pounds. Since 5 pounds feeds 3 dogs for 4 days, then 5 pounds will feed 12 dogs for 1 day. Then the dogs require 35 pounds for 7 days.

Learn to regroup mixed numbers to subtract.

Jimmy and his mother planted a tree when it was 1 ft tall. Now the tree is 2 ft tall. How much has the tree grown since it was planted? 3 4 __ 1 1 4 __ 3 The difference in the heights can be represented by 2 – 1 . 1 4 __ 3 You will need to regroup 2 because the fraction in 1 is greater than . 1 4 __ Divide one whole of 2 into fourths.

The tree has grown ft since it was planted. 1 4 __ 5 4 __ 2 1 1 4 1 4 __ 5 4 __ Regroup 2 as 1 . 3 4 __ 3 4 __ –1 – 1 ______ ______ 1 4 1 4 2 4 __ 1 2 __ = 1 2 __ The tree has grown ft since it was planted.

Additional Example 1A: Regrouping Mixed Numbers Subtract. Write each answer in simplest form. 2 3 __ 6 – 3 6 – 4 = 2 Estimate the difference. 3 __ Write 6 as a mixed number with a denominator of 3. Rename 6 as 5 + . 3 __ 6 5 2 3 __ 2 3 __ Subtract the fractions and then the whole numbers. –3 –3 ______ ______ 1 3 __ 2 1 3 __ 2 is close to the estimate of 2. The answer is reasonable.

Additional Example 1B: Regrouping Mixed Numbers Subtract. Write each answer in simplest form. 1 3 __ 3 4 __ 5 – 2 5 – 3 = 2 Estimate the difference. 4 12 __ 16 12 __ 5 4 The LCM of 4 and 3 is 12. Rename 5 as 4 + 1 = 4 + + . 4 12 __ 9 12 __ 9 12 __ –2 –2 ______ ______ 7 12 __ Subtract the fractions and then the whole numbers. 2 7 12 __ 2 is close to the estimate of 2. The answer is reasonable.

Check It Out: Example 1A Subtract. Write each answer in simplest form. 6 __ 5 6 __ 7 – 2 7 – 3 = 4 Estimate the difference. 1 6 __ 7 6 __ 1 6 __ 1 6 __ 6 __ 1 6 __ 7 6 Rename 7 as 6 + 1 = 6 + + . 5 6 __ 5 6 __ Subtract the fractions and then the whole numbers. –2 –2 ______ ______ 2 6 __ 1 3 __ 4 Write the answer in simplest form. = 4 1 3 __ 4 is close to the estimate of 4. The answer is reasonable.

Check It Out: Example 1B Subtract. Write each answer in simplest form. 2 5 __ 7 10 __ 8 – 6 8 – 7 = 1 Estimate the difference. 4 10 __ 14 10 __ 10 is a multiple of 5, so 10 is a common denominator. 8 7 4 10 __ 4 10 __ 10 __ 4 10 __ 7 10 __ 7 10 __ Rename 8 as 7 + 1 = 7 + + . –6 –6 ______ ______ 7 10 __ Subtract the fractions and then the whole numbers. 1 7 10 __ 1 is close to the estimate of 1. The answer is reasonable.

Additional Example 2A: Measurement Application Li is making a quilt. She needs 15 yards of fabric. Li has 2 yards of fabric. How many more yards does she need? 3 4 __ 4 __ Write 15 as a mixed number with a denominator of 4. Rename 15 as 14 + . 15 14 4 __ 3 4 __ 3 4 __ –2 –2 Subtract the fractions and then the whole numbers. ______ ______ 1 4 __ 12 1 4 __ Li needs another 12 yards of fabric.

Additional Example 2B: Measurement Application If Li uses 11 yards of fabric, how much of the 15 yards will she have left? 1 6 __ 6 __ Write 15 as a mixed number with a denominator of 6. Rename 15 as 14 + . 15 14 6 __ 1 6 __ 1 6 __ –11 –11 Subtract the fractions and then the whole numbers. ______ ______ 5 6 __ 3 5 6 __ Li will have 3 yards of fabric.

Check It Out: Example 2A Peggy is making curtains. She needs 13 yards of fabric. Peggy has 4 yards of fabric. How many more yards does she need? 5 6 __ 6 __ Write 13 as a mixed number with a denominator of 6. Rename 13 as 12 + . 13 12 6 __ 5 6 __ 5 6 __ –4 –4 Subtract the fractions and then the whole numbers. ______ ______ 1 6 __ 8 1 6 __ Peggy needs another 8 yards of fabric.

Check It Out: Example 2B If Peggy uses 9 yards of fabric, how much of the 13 yards will she have left? 1 4 __ 4 __ Write 13 as a mixed number with a denominator of 4. Rename 13 as 12 + . 13 12 4 __ 1 4 __ 1 4 __ –9 –9 Subtract the fractions and then the whole numbers. ______ ______ 3 4 __ 3 3 4 __ Peggy will have 3 yards of fabric left.

Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems

Lesson Quiz Subtract. Write each answer in simplest form. 1. 2. 4 3 1. 2. 3. 4. 5. Irena put 10 cups of food in the bird feeder. The birds ate 3 cups. How many cups are left? 4 9 10 __ 3 5 7 __ 1 7 9 __ 5 13 16 __ 3 8 __ 6 cups 5 8 __

Lesson Quiz for Student Response Systems 1. Subtract and identify the answer in simplest form. A. C. B. D.

Lesson Quiz for Student Response Systems 2. Subtract and identify the answer in simplest form. A. C. B. D.

Lesson Quiz for Student Response Systems 3. Subtract and identify the answer in simplest form. A. C. B. D.

Lesson Quiz for Student Response Systems 4. A Dachshund weighs pounds. A Dandi Dinmont Terrier weighs 18 pounds. What is the difference, in pounds, in their weights? A. C. B. D.