Students will be able to fluently add and subtract multi-digit whole numbers using the standard algorithm, demonstrating understanding of place value and regrouping.
Mastering the standard algorithm for addition and subtraction is a fundamental skill that empowers students to confidently tackle more complex mathematical problems and apply these operations in everyday situations, from managing money to understanding data.
Review the Algorithm Adventure Slides to familiarize yourself with the content and example problems. - Prepare the whiteboard or projector for displaying slides and working through examples. - Print or prepare to display the Algorithm Warm Up and Algorithm Cool Down. - Ensure all generated materials are reviewed as needed.
Step 1
Warm-Up: Ready, Set, Add/Subtract!
2 minutes
Display the Algorithm Warm Up on the board. - Ask students to quickly solve the mental math problems or simple addition/subtraction problems. - Briefly review answers as a class, focusing on quick recall and basic number sense.
Step 2
Introduction: What's the Standard Algorithm?
5 minutes
Begin by presenting the 'What's an Algorithm?' slide from the Algorithm Adventure Slides. - Explain that an algorithm is just a set of steps to solve a problem. - Introduce the standard algorithm for addition, emphasizing lining up place values and starting from the ones place (regrouping as needed). - Work through the 'Adding Big Numbers (Example 1)' slide together, step-by-step, narrating the process clearly. - Repeat the process for subtraction using the 'Subtracting Big Numbers (Example 1)' slide, highlighting borrowing/regrouping when necessary.
Step 3
Guided Practice: Let's Do It Together!
6 minutes
Move to the 'Your Turn! (Guided Practice)' slides for addition and subtraction on the Algorithm Adventure Slides. - Guide students through solving one addition and one subtraction problem together, step-by-step. - Encourage students to participate by calling out steps, explaining their reasoning, and identifying place values. - Provide immediate feedback and clarification on any misconceptions. - Ensure students are correctly lining up numbers and performing regrouping/borrowing.
Step 4
Cool-Down: Quick Check
2 minutes
Distribute or display the Algorithm Cool Down. - Ask students to solve the single problem independently. - Collect the cool-down slips or quickly review the answer as a class to gauge overall understanding of the lesson objectives.
Slide Deck
Algorithm Adventure: Adding & Subtracting Big Numbers!
Get ready to become a math superstar!
Welcome students and introduce the exciting topic of the day. Briefly mention that they'll become 'Algorithm Superstars'!
What's an Algorithm?
An algorithm is a step-by-step way to solve a math problem.
Today, we'll learn the 'standard algorithm' for adding and subtracting big numbers!
Explain what an algorithm is in simple terms: a step-by-step method to solve a problem. Emphasize that the 'standard algorithm' is just a common, reliable way we all learn.
Adding Big Numbers: Let's Try One!
Example: 3,456 + 1,789
3,456
1,789
Remember to:
Line up your numbers by place value.
Start adding from the ones column.
Regroup (carry over) if your sum is 10 or more.
Walk through this example slowly. Emphasize lining up place values (ones, tens, hundreds, thousands) and starting from the ones column. Demonstrate regrouping (carrying over) clearly.
Subtracting Big Numbers: Your Turn!
Example: 5,234 - 2,876
5,234
2,876
Remember to:
Line up your numbers by place value.
Start subtracting from the ones column.
Regroup (borrow) if the top digit is smaller than the bottom digit.
Walk through this subtraction example. Again, stress lining up numbers and starting from the ones. Clearly demonstrate borrowing (regrouping for subtraction) across place values.
Guided Practice: Try This Addition!
Problem: 4,817 + 2,305
4,817
2,305
What's the first step? Which column do we start with?
Give students a moment to think or try this on scratch paper. Then, work through it together as a class, encouraging students to dictate the steps.
Guided Practice: Try This Subtraction!
Problem: 7,500 - 3,128
7,500
3,128
Where do we need to regroup (borrow) first?
Follow the same process as the previous slide for subtraction. Ask students where they might need to borrow.
Great Job, Superstars!
You've practiced using the standard algorithm for addition and subtraction!
Key takeaways:
Line up your numbers by place value.
Always start from the ones column.
Don't forget to regroup (carry or borrow)!
Summarize the key learning points. Reiterate the importance of lining up numbers and understanding regrouping/borrowing.
Warm Up
Algorithm Warm Up!
Directions: Answer the following questions.
What is 50 + 30?
What is 90 - 20?
True or False: When you add big numbers, you always start adding from the very left side?
Cool Down
Algorithm Cool Down!
Directions: Solve the problem below.
Problem: 6,789 + 1,234
How confident do you feel about adding and subtracting big numbers using the standard algorithm?
