1. Common Core 3.NBT.2 ACOS 3.11 and 2003 COS 3.2 Marilyn Whatley Lincoln Elementary

2. *A fact family is a set of related addition and subtraction number sentences that use the same numbers. You are practicing fact families every time you use XTRAMATH.com Examples of fact families: 3 + 4 = 7 7 – 4 = 3 4 + 3 = 7 7 – 3 = 4 2 + 8 = 10 10 – 8 = 2 8 + 2 = 10 10 – 2 = 8

5. I can fluently add and subtract numbers.  Fluently means that I can get the correct answers when I add and subtract and that I can work without wasting my time.  I will make a plan as I solve a problem and use strategies that I know.

6.  Watch and listen as I model how to use what I know (a strategy) to help me solve a subtraction problem.  (next 5 slides)

7. Tom delivered 47 papers on Sunday. Brian delivered 59 on Monday.. How many more papers did Brian deliver than Tom? This part is the information I will need to solve the problem. I need to read it carefully. It is a good idea to read it twice and make a picture in my head. This part is the question. It tells me what I need to find an answer for.

8. First, I picture what the information says: N N N N N N N N N N N N N N N N N N N N N N N N N N Tom Brian Brian delivered MORE. I need to find out HOW MANY MORE.

9. Then I read the question to see what to do with the information.  How many more papers did Brian deliver than Tom?  I know that HOW MANY MORE means that there is a difference in two numbers, so I think I need to subtract.

10. N N N N N N N N N N N N N N Tom Brian I need to subtract, or TAKE AWAY 47 from the larger Number of 59. N N N N N N N N N N N N The white Ns show the number of papers that Tom delivered. When I take that many away from the red papers of Brian, I see a difference of 12 papers. So 59 – 47 = 12

11. Now, I need to EXPLAIN how I got my answer. I subtracted the smaller number 47 from the larger number 59 and got a difference of 12 papers. 59 Brian’s papers - 47 Tom’s papers 12 difference I can use words, numbers, or both to explain my answer !

12. Now, let’s work a problem together. Turn to the next page in your Math Journal. Put today’s date at the top. Put pencils down because first, we have to read the information. Then we need to “picture the information”.

13. There are 16 third graders and 22 fourth graders on the playground. How many more fourth graders are on the playground than third graders? What is the information? Now picture that in your mind.

14. Cccccc ccccccc ccc 3 rd graders Cccccccccc ccccccccccc c 4 th graders There are 16 third graders and 22 fourth graders on the playground. How many more fourth graders are on the playground?

15. Cccccc ccccccc ccc 3 rd graders Cccccccccc ccccccccccc c 4 th graders There are 16 third graders and 22 fourth graders on the playground. How many more fourth graders are on the playground? What is the question? What should I do?

16. Cccccc ccccccc ccc 3 rd graders Cccccc cccc 4thgraders How many more fourth graders are on the playground? I need to subtract to find the difference.

17. 22 fourth graders - 16 third graders 6 Work the problem in your journal. Be sure to explain how you got your answer! 1 12

18. Examples of answers: I subtracted the 16 third graders from the 22 fourth graders and got a difference of 6 more fourth grade students. I took away 16 from 22 to find out there were 6 more fourth graders than third graders. 22 fourth grade students - 16 third grade students 6 more fourth graders than third graders

19. Now, it is YOUR turn to work with a partner to solve a problem. Remember to read the information. Picture it in your mind. Read the question. Make a plan. Both partners work the problem in their math journals. Explain how you got your answer!

20. There are 15 fourth graders and 23 fifth graders in the gym. How many more fifth graders are in the gym than fourth graders?

21. Share students’ work using ELMO document camera. More practice for students to try ON THEIR OWN on the next slides.

22. There are 35 horses and 24 cows in the barn. How many more horses are there than cows?

23. Sara and her dad went fishing. Sara caught 12 fish and her dad caught 21. How many more fish did dad catch than Sara?

24. First graders went on a field trip. 53 rode on the first bus and 57 rode on the second bus. How many fewer first graders rode the first bus than the second bus?

25. On Sunday, Mel texted her friends 47 times. On Monday, Mel texted her friends only 32 times because she had homework to do. How many fewer times did Mel text on Monday than Sunday?