This math lesson teaches students how to add two-digit numbers. It provides two examples, showing how to line up the numbers in columns, add right columns and carry numbers over when sums are greater than 9, then add the left columns. Key terms defined include sum, equation, and addition. Students are asked to practice an addition problem and show their work step-by-step before teaching the lesson.

1. Math Lesson! Get Ready for some fun in math!

2. Let’s Learn! Today we are going to learn how to add 2-digit numbers. We will start with a few examples and relate them back to the colored blocks. You will see how to get the sum of two different numbers using the addition property

3. Example # 1 15 + 12 = 27 First you line up 15 and 12 into columns that match up nicely. It should look something like this: 15 12

4. Example # 1 After you line them up, you add the right column and write the number below. It should look something like this: 15 12 7

5. Example #1 After you add the right column, you then add the left column and write the number below. It should look something like this: 15 12 27

6. Example # 1 After you add both columns and write the number below, your problem is complete!!

7. Example # 2 15+15=20 First you line up 15 and 15 intwo columns that match up nicely. It should look something like this: 15 15

8. Example # 2 After you line them up, you add the right column and write the number below. It should look something like this: In this case, 5+5=10 which is a two digit number. Since there are two digits, the 1 is carried over to the left column for future adding. 15 15 0

9. Example # 2 After you add the right column, you add the left column, keeping in mind that there is the 1 that is carried over from the column on the right. Keep in mind that the reason that there is a 3 underneath the 1’s is because the 1 was carried over to the left column when 5+5 was added to equal 10 (a two digit number) It should look something like this: 15 15 30

10. Example # 2 After you add both columns and write the number below, your problem is complete!

11. Some definitions Keep in mind that there are some definitions that you will need to know. Here are a few: Sum: “Summation is the addition of a set of numbers; the result is their sum or total” Equation: “An equation is a mathematical statement, in symbols, that two things are exactly the same (or equivalent)” Addition: “Addition is the mathematical process of combining quantities”

12. Your Turn! Ok class, now it is your turn to show me what you have learned. Please take a piece of paper and write your equation down. Show step by step how to add your two numbers together. Once you are done, come show me so that I can make sure it is correct. Once it has been checked by me, you can then copy it down on the transparency and prepare to teach the class :)