Regrouping: Also known as FUNNY NUMBERS!

1. Regrouping: Also known as FUNNY NUMBERS! How would you write 5 ones? 5 x 1 = 5 9 x 1 = 9 How would you write 9 ones? 11 x 1 = 11 How would you write 11 ones? How would you write 25 ones? 25 x 1 = 25 Anything times “1” is the same number. So 1,000,000 x 1 is still 1,000,000!

2. So the number of ones you have is how much you have! What about tens? How would you write 5 tens? 5 x 10 = 50 How would you write 9 tens? 9 x 10 = 90 How would you write 11 tens? 11 x 10 = 110 How would you write 25 tens? 25 x 10 = 250 What is happening? For tens, you add “1” zero.

3. So, for tens, you add “1” zero. What happens with hundreds? 2 x 100 = 200 How would you write 2 hundreds? How would you write 9 hundreds? 9 x 100 = 900 How would you write 13 hundreds? 13 x 100 = 1300 19 x 100 = 1900 How would you write 19 hundreds? For hundreds, you add “2” zeros. What is happening?

4. So, for tens, you add “1” zero. And for hundreds, you add “2” zeros. What about thousands? 4 x 1000 = 4000 How would you write 4 thousands? How would you write 7 thousands? 7 x 1000 = 7000 How would you write 11 thousands? 11 x 1000 = 11000 19 x 1000 = 19000 How would you write 19 thousands? For thousands, you add “3” zeros. What is happening?

5. Let’s review… For ones, So, for tens, you add And for hundreds, you add For thousands, you add the number of ones is the number. “1” zero. “2” zeros. “3” zeros.

6. Let’s try a problem together. What means the same thing as 5 tens and 11 ones? Hmm… 5 tens means 50and 11 ones means 11. So, I just add 50 + 11. And that equals 61. My conclusion is that 5 tens and 11 ones means the same thing as 61.

7. Let’s try another. What means the same thing as 12 tens and 17 ones? 120 17 Hmm… 12 tens means _____ and 17 ones means _____. 120 17 137 So, I just add ____ + _____. And that equals _____.

8. What about this? What means the same thing as 15 hundreds, 18 tens, 12 ones? 1500 180 Hmm… 15 hundreds means _____ and 18 tens means _____ And 12 ones means ______. 12 1500 180 12 So, I just add ____ + _____ + _____. And that equals _____. 1692

9. What about this? What means the same thing as 6 thousands, 15 hundreds, 18 tens, 12 ones? 6000 Let’s see… 6 thousands means _________ 15 hundreds means ______ 18 tens means ______ 12 ones means ______. 1500 180 12 6000 1500 180 12 So, I just add______ + ______ + ______ + ______ . And that equals _______. 7692

10. Try this! What means the same thing as 8 thousands, 16 hundreds, 16 tens, 16 ones? 8000 Let’s see… 8 thousands means _________ 16 hundreds means ______ 16 tens means ______ 16 ones means ______. 1600 160 16 8000 1600 160 16 So, I just add______ + ______ + ______ + ______ . And that equals _______. 9776

11. Now let’s switch gears! What means the same as 6,429? I have to work through ALL of the following problems! A. B. 5000 6 thousands means _________ 14 hundreds means ______ 12 tens means ______ 9 ones means ______. 6000 5 thousands means _________ 14 hundreds means ______ 12 tens means ______ 19 ones means ______. 1400 1400 120 120 9 19 That adds up to 7,529. Nope! That adds up to 6,539. Nope! D. C. 6 thousands means _________ 14 hundreds means ______ 12 tens means ______ 19 ones means ______. 6000 5 thousands means _________ 13 hundreds means ______ 11 tens means ______ 19 ones means ______. 5000 1400 1300 120 110 19 19 That adds up to 7,539. Nope! That adds up to 6,429. Bingo!!

12. Here we go again! What means the same as 9,584? I have to work through ALL of the following problems! A. B. 8000 9 thousands means _________ 14 hundreds means ______ 15 tens means ______ 14 ones means ______. 9000 8 thousands means _________ 15 hundreds means ______ 18 tens means ______ 19 ones means ______. 1400 1500 150 180 14 19 That adds up to 10,564. No way! That adds up to 9,684. Close, but no! D. C. 8 thousands means _________ 14 hundreds means ______ 17 tens means ______ 14 ones means ______. 8000 9 thousands means _________ 13 hundreds means ______ 17 tens means ______ 14 ones means ______. 9000 1400 1300 170 170 14 14 That adds up to 9,584. Yippee! That adds up to 10,484. Nope!!

13. Do this problem on a piece of paper. Problem 1 Which means the same as 8,765? • 8 thousands + 7 hundreds + 16 tens + 15 ones • 8 thousands + 17 hundreds + 6 tens + 5 ones • 8 thousands + 6 hundreds + 15 tens + 15 ones • 7 thousands + 17 hundreds + 15 tens + 16 ones 8000 + 700 + 160 + 15 = 8,865 8000 + 1700 + 60 + 5 = 9,765 8000 + 600 + 150 + 15 = 8,765 7000 + 1700 + 150 + 16 = 8,866

14. Do this problem on a piece of paper. Problem 2 Which means the same as 4,321? • 4 thousands + 3 hundreds + 12 tens + 11 ones • 3 thousands + 3 hundreds + 12 tens + 1 one • 3 thousands + 13 hundreds + 11 tens + 11 ones • 3 thousands + 12 hundreds + 11 tens + 11 ones 4000 + 300 + 120 + 11 = 4,431 3000 + 300 + 120 + 1 = 3,421 3000 + 1300 + 110 + 11 = 4,421 3000 + 1200 + 110 + 11 = 4,321

15. Do this problem on a piece of paper. Problem 3 Which means the same as 2,468? • 2 thousands + 4 hundreds + 6 tens + 18 ones • 1 thousand + 13 hundreds + 15 tens + 18 ones • 1 thousand + 14 hundreds + 15 tens + 18 ones • 2 thousands + 13 hundreds + 15 tens + 18 ones 2000 + 400 + 60 + 18 = 2,478 1000 + 1300 + 150 + 18 = 2,468 1000 + 1400 + 150 + 18 = 2,568 2000 + 1300 + 150 + 18 = 3,468

16. When you see a problem like this, REMEMBER to work out each problem to find one that matches the given number! Perseverance is the KEY!