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**Chapter 3**Subtraction Click the mouse or press the space bar to continue. Splash Screen**Subtraction**3 Lesson 3-1Two-Digit Subtraction Lesson 3-2Estimate Differences Lesson 3-3Subtract Money Lesson 3-4Problem-Solving Skill: Reasonable Answers Lesson 3-5Three-Digit Subtraction with Regrouping Lesson 3-6Problem-Solving Investigation: Choose a Strategy Lesson 3-7Subtract Greater Numbers Lesson 3-8Subtract Across Zeros Lesson 3-9 Algebra: Expressions and Number Sentences Chapter Menu**Two-Digit Subtraction**3-1 Five-Minute Check (over Chapter 2) Main Idea California Standards Example 1 Example 2 Lesson 1 Menu**Two-Digit Subtraction**3-1 • I will subtract two-digit and one-digit numbers. Lesson 1 MI/Vocab**Two-Digit Subtraction**3-1 Standard 3NS2.1Find the sumor difference of two whole numbers between 0 and 10,000. Lesson 1 Standard**Two-Digit Subtraction**3-1 A lion can run 50 miles per hour. A camel can run 20 miles per hour. How much faster can the lion run? You can use subtraction to solve the problem. You need to find 50 – 20. Lesson 1 Ex1**Two-Digit Subtraction**3-1 50 50 0 – 20 – 20 Step 1 Subtract ones. 0ones–0ones=0ones 0 Step 2 Subtract tens. 5tens–2tens=3tens 3 Answer: So, the lion can run 30 mph faster than the camel. Lesson 1 Ex1**Two-Digit Subtraction**3-1 Check You can use addition to check your answer. 30 + 20 = 50 So the answer is correct. Lesson 1 Ex1**Two-Digit Subtraction**3-1 A cheetah can run up to 70 miles per hour. A rabbit can run up to 20 mph. How much faster can a cheetah run? • 50 mph • 40 mph • 55 mph • 60 mph Lesson 1 CYP1**Two-Digit Subtraction**3-1 32 – 25 A giraffe can run 32 miles per hour. An elephant can run 25 miles per hour. How much faster can the giraffe go? You need to find 32 – 25. Step 1 Subtract ones. You cannot take 5 ones from 2 ones. 12 2 Regroup: 1 ten as 10 ones. 2 ones + ten ones = 12 ones 7 12 ones – 5 ones = 7ones Lesson 1 Ex2**Two-Digit Subtraction**3-1 12 2 7 32 – 25 Step 2 Subtract tens. 2 tens – 2 tens = 0 tens 0 Answer: So, the giraffe can run 7 mph faster than the elephant. Lesson 1 Ex2**Two-Digit Subtraction**3-1 Check You can use addition to check your answer. 7 + 25 = 32 So the answer is correct. Lesson 1 Ex2**Two-Digit Subtraction**3-1 A fox can run 42 miles per hour and a chicken can run 9 miles per hour. How much faster is the fox? • 40 mph • 37 mph • 43 mph • 33 mph Lesson 1 CYP2**Estimate Differences**3-2 Five-Minute Check (over Lesson 3-1) Main Idea California Standards Example 1 Example 2 Lesson 2 Menu**Estimate Differences**3-2 • I will estimate differences using rounding and front-end estimation. Lesson 2 MI/Vocab**Estimate Differences**3-2 Standard 3NS1.4Round off numbers to 10,000 to the nearest ten, hundred, and thousand. Standard 3NS2.1 Find the sum ordifference of two whole numbers between 0 and 10,000. Lesson 2 Standard**Estimate Differences**3-2 62 60 18 20 Rosalinda bought a package of 62 carrots and a bag of 18 potatoes. About how many more carrots were there? You need to estimate 62 – 18. Step 1 Round each number to the nearest ten. Lesson 2 Ex1**Estimate Differences**3-2 60 – 20 Step 2 Subtract. 40 Answer: So, there are about 40 more carrots. Lesson 2 Ex1**Estimate Differences**3-2 Noah bought a bouquet of flowers with 19 roses and 8 daisies. About how many more roses where there? • 11 • 10 • 12 • 8 Lesson 2 CYP1**Estimate Differences**3-2 It is 2,816 miles from Washington, D.C. to San Francisco and 671 miles from Washington, D.C. to Chicago. About how many miles further is it to San Francisco? Round to the nearest hundred. You need to estimate 2,816 – 671. Lesson 2 Ex2**Estimate Differences**3-2 2,816 2,800 671 700 Step 1 Round each number to the nearest hundred. Lesson 2 Ex2**Estimate Differences**3-2 2,800 – 700 Step 2 Subtract. 2,100 Answer:So, San Francisco is about 2,100 miles further than Chicago. Lesson 2 Ex2**Estimate Differences**3-2 It is 142 miles from Columbus, Ohio to Cleveland, Ohio, and 106 miles from Columbus to Cincinnati, Ohio. About how many miles further is it to Cleveland? Round to the nearest ten. • 136 miles • 36 miles • 30 miles • 100 miles Lesson 2 CYP2**Subtract Money**3-3 Five-Minute Check (over Lesson 3-2) Main Idea California Standards Example 1 Example 2 Lesson 3 Menu**Subtract Money**3-3 • I will subtract money. Lesson 3 MI/Vocab**Subtract Money**3-3 Standard 3NS2.1Find the sum or difference of two whole numbers between 0 and 10,000. Lesson 3 Standard 1**Subtract Money**3-3 Standard 3NS3.3 Solve problems involving addition, subtraction, multiplication, and divisionof money amounts in decimal notation and multiply and divide money amounts in decimal notation by using whole-number multipliers and divisors. Lesson 3 Standard 2**Subtract Money**3-3 Fina had 86 cents. She bought a bag of peanuts for 73 cents. How much change did she receive? You need to find the difference between 86¢ and 73¢. Lesson 3 Ex1**Subtract Money**3-3 86¢ – 73¢ One Way: Subtract Cents Subtract the ones. Subtract the tens. 3 1 ¢ Place the cents sign after the difference. Lesson 3 Ex1**Subtract Money**3-3 $0.86 – $0.73 Another Way: Subtract Dollars $0.13 Answer: So, the difference is 13 cents. Lesson 3 Ex1**Subtract Money**3-3 Check for Reasonableness Since 13¢ is close to the estimate of 20¢, the answer is reasonable. Check Use addition. So, the answer is correct. Lesson 3 Ex1**Subtract Money**3-3 Marsalla had $0.49 and spent $0.28 on a pencil. How much change did she receive? • 21¢ • 20¢ • 10¢ • 22¢ Lesson 3 CYP1**Subtract Money**3-3 Estimate $43 – $34 $40 – $30 = $10 Marisa paid $34 for a pair of jeans. Dona paid $43. How much more did Dona pay? You need to find the difference between $34 and $43. When you subtract money, you often need to regroup. Lesson 3 Ex2**Subtract Money**3-3 $43 – $34 Regroup 1 ten as 10 ones. 3 13 Subtract the ones. Subtract the tens. 9 $ Place the dollar sign before the difference. Answer: So, the difference is $9. Lesson 3 Ex2**Subtract Money**3-3 Check for Reasonableness Since $9 is close to the estimate of $10, the answer is reasonable. Check Use addition. So, the answer is correct. Lesson 3 Ex2**Problem-Solving Skill: Reasonable Answers**3-4 Five-Minute Check (over Lesson 3-3) Main Idea California Standards Example 1: Problem-Solving Skill Lesson 4 Menu**Problem-Solving Skill: Reasonable Answers**3-4 • I will decide whether an answer is reasonable. Lesson 4 MI/Vocab**Problem-Solving Skill: Reasonable Answers**3-4 Standard 3MR3.1Evaluate the reasonableness of the solution in the context of the original situation. Standard 3NS2.1 Find the sum or difference of two whole numbers between 0 and 10,000. Lesson 4 Standard 1**Problem-Solving Skill: Reasonable Answers**3-4 Kenji bought a box of 85 straws of 3 different colors. He found that 53 straws were blue and green. Kenji thinks that about 30 straws are pink. Is this a reasonable answer? Lesson 4 Ex1**Problem-Solving Skill: Reasonable Answers**3-4 Understand What facts do you know? • There are 85 straws. • There are 3 colors of straws. • There are 53 blue and green straws. What do you need to find? • Decide whether 30 is a reasonable amount of pink straws. Lesson 4 Ex1**Problem-Solving Skill: Reasonable Answers**3-4 Plan Use subtraction to find the number of pink straws. Then compare the answer to 30. Lesson 4 Ex1**Problem-Solving Skill: Reasonable Answers**3-4 85 – 53 32 Solve Subtract the number of blue and green straws from the total number of straws. Answer: Since 32 is close to 30, it is reasonable to say that 30 of the straws are pink. Lesson 4 Ex1**Problem-Solving Skill: Reasonable Answers**3-4 85 90 – 53 – 50 40 Check Look back at the problem. Estimate by rounding. So, the answer makes sense for the problem. Lesson 4 Ex1**Three-Digit Subtraction with Regrouping**3-5 Five-Minute Check (over Lesson 3-4) Main Idea California Standards Example 1 Example 2 Subtract Three-Digit Numbers with Regrouping Lesson 5 Menu**Three-Digit Subtraction with Regrouping**3-5 • I will subtract three-digit numbers with regrouping. Lesson 5 MI/Vocab**Three-Digit Subtraction with Regrouping**3-5 Standard 3NS2.1Find the sum ordifference of two whole numbers between 0 and 10,000. Standard 3MR2.1 Use estimation to verify the reasonableness of calculated results. Lesson 5 Standard 1