3 6 Subtracting with an Expanded Algorithm Today

3 -6: Subtracting with an Expanded Algorithm Today we will learn… How to solve 3 -digit subtraction problems using the expaned algorithm strategy Vocabulary • Minuend • Subtrahend • Difference

Vocabulary Review 12 - 5 = 7 ? ? ? • What vocabulary word the largest number? (the total) • What vocabulary word describes the number you are subtracting? (2 nd number) • What vocabulary word describes the answer to a subtraction problem?

How to subtract with expanded algorithm: 242 - 131 = ? Step 1: Break the problem into smaller problems. Start by subtracting the hundreds. Step 2: Subtract the tens. 142 – 30 = 112 242 – 100 = 142 Step 3: Subtract the ones 112 – 1 = 111 So, 242 - 131 = 111

Let’s try one together! Use your whiteboard to follow along as we solve: 738 - 124 1. Subtract the hundreds: • 738 - 100 = 638 2. Subtract the tens: • 638 - 20 = 618 3. Subtract the ones: • 618 - 4 = 614 So, 738 – 124 = 614

Let’s try another one! Use your whiteboard to follow along as we solve: 462 - 131 1. Subtract the hundreds: • 462 - 100 = 362 2. Subtract the tens: • 362 - 30= 332 3. Subtract the ones: • 332 - 1 = 331 So, 462 – 131= 332

Work with your partner Use the expanded algorithm strategy to solve these on your whiteboards A. 738 - 523 B. 755 - 315 C. 336 -215

Problem Solving Mr. Brown sells flowers. He has 417 red roses and 232 yellow roses. How many more red roses than yellow roses does Mr. Brown have? Complete the bar diagram and write a number sentence. Carefully read the problem. Underline the question. [Bracket] important words and numbers. Eliminate unnecessary information. Solve and check your work.