1. Matt Carrino Long Division for Fourth-Grade Math

2. What is long division? ► Process of division ► Divisor is usually a large number ► Each step of the division is written out

3. When is long division needed? ► Either the divisor or the dividend contain 2 digits or more ► You cannot figure out the problem in your head ► Answers cannot be found in your times tables

4. Problems that do not need long division ►P►P►P►Problems that can be found in your times tables ►E►E►E►Easy enough to figure out in your head ►P►P►P►Problems we either learned or similar ones to those

5. For example… ► 10 / 5 = ? ► 81 / 9 = ? ► 4 / 2 = ? ►2►2 ►9►9 ►2►2

6. Problems that need long division… ► Are more complicated than those problems ► Usually have divisors and dividends of 2 digits or more ► Require you to learn from this presentation!

7. For example… ► 2222 / 11 ► 240 / 4 ► 999 / 3

8. ► Can you figure out those problems in your head? ► You would need a calculator … ► unless, you took the steps in the following slides in order to solve the problems

9. To Begin Long Division ► Take the first digit of the dividend, and see if it is divisible by 25. ► 4 / 25 ► 4 is not divisible by 25 ► So, place a 0 above the 4

10. To Begin Long Division ► Multiply the answer by the divisor.. Put result under number divided into ► Subtract the bottom number from the top number

11. To Begin Long Division ► Bring down the next number of the dividend. ► Divide this number by the divisor.

12. The Process of Long Division ► 25 goes into 42 one time. Put that number at the top. ► Now, multiply that 1 by 25 and put it under 42.

13. The Process of Long Division ► To get remainder, subtract bottom from top ► Bring down the next number of the dividend.

14. The Process of Long Division ► Now, divide 175 by 25, the same way we have been doing ► ____ 25) 175 25) 175 ► 25 / 1 = 0, so ► 0 ___ ___ 25)175 25)175 ► 25 / 7 =0, so ► 00 ___ 25)175 We are left with 175 /25

15. The Process of Long Division ► 175 /25. How many times does 25 go into 175? ► 25 * 7 = 175, so ► 7 ___ ___ 25)175 25)175 175 175 --- --- 0

16. The Process of Long Division ► 7 is our answer to this part of the process: ► So,

17. The Process of Long Division ► Now, take your answer and multiply by the divisor. Put the result under the number divided into.

18. The Process of Long Division ► Subtract the bottom number from the top number

19. The Process of Long Division ► There are no more answers to bring down, so our answer is…… 17!!!!!!!!

20. Bibliography ► Long Division. (2004). Math is Fun. Retrieved December 4, 2004, from http://www.mathsisfun.com/long_division.html December 4, 2004, from http://www.mathsisfun.com/long_division.html http://www.mathsisfun.com/long_division.html ► Long Division. (2001). Homo Excelsior. Retrieved December 4, 2004, from http://www.homoexcelsior.com/omega.db/datum /mathematics/long_division/6729 http://www.homoexcelsior.com/omega.db/datum