An AskERIC Lesson Plan
AUTHOR: Lauren Evans, Su-Valley Junior/Senior High School, Talkeetna, Alaska
GRADE LEVEL: MATH 4-12 (I teach it to 7-8)
OVERVIEW:
Students are having trouble with CARRYING in ADDITION problems or:
students are slow when adding
students want to add faster and more accurately
students want to add without pencil and paper
PURPOSE:
This gives kids an alternative way of adding if they have trouble with 'carrying'. It is also faster and more accurate for MOST kids.
I have all of the kids try this then ENCOURAGE the ones that have trouble with addition to use it all of the time.
The biggest problem is that a few kids think it is sort of cheating to use this method because it doesn't follow th d26 e 'rules' of addition. Once convinced it is OKAY to use, they like it.
This also works for multiplying, but that's another lesson.
OBJECTIVES:
Upon completion of this lesson, the student will be able to add correctly and quickly.
RESOURCES/MATERIALS:
Paper, pencil, addition problems.
ACTIVITIES:
1) problem - 35
+ 24
----
2) Add from LEFT TO RIGHT (the OLD way is to
add the ONES first and then carry)
Add the TENS first 30
+ 20
------
50
Then add the ONES 5
+ 4
-----
9
Then add the answers 50
+ 9
----
59 NO CARRYING
TIP * Start with problems that require NO carrying
(when using the OLD method) so they get the idea...
progress to tougher problems (below).
steps (1) (2) (3)
EXAMPLES: 378 300 70 8
+ 958 + 900 + 50 + 8
------ ------ ---- ---
1200 to 1200 (4) 120 to--------- 120 (add)
16 to---------------- 16 ------ 1336
THE ANSWER!!! steps (1) (2) (3) (4) (5)
EXAMPLE: 5830 5000 800 30 0 2967 2000 900 60 7 836 800 30 6 + 38566 + 30000 + 8000
+ 500 + 60 + 6 -------- ------- ------ ----- ---- --- 30000 to- 30000 15000
to-----------15000 (6) 3000 to------------------ 3000 add 180
to---------------------------180 19*to----------------------------------19 -------- 48199
THE ANSWER!!! TIP: If the above example had a list of sums that ended with a 20
*(rather than 19), the list can be added just as the original problem was added so that
the student won't have to carry here either. See the sample below.
EXAMPLE:
5830
2967
836
+ 38567
--------
30000
15000
3000
180 Here the 80 + 20 = 100. Using
20 the old method of adding, the
------- '1' would have to be carried...
40000 here we just add from left to
8000 right again to get rid of that
100 problem...
100
-------
48200 THE ANSWER!!!
TYING IT TOGETHER: Do math problems and test the kids for speed and accuracy. I usually do a pretest without telling the kids why...having them time the test. I keep this and give it again a couple/three weeks later once they know the new method. They seldom are less accurate or take more time.
May 19940These lesson plans are the result of the work of the teachers who have attended the Columbia Education Center's Summer Workshop. CEC is a consortium of teacher from 14 western states dedicated to improving the quality of education in the rural, western, United States, and particularly the quality of math and science Education. CEC uses Big Sky Telegraph as the hub of their telecommunications network that allows the participating teachers to stay in contact with their trainers and peers that they have met at the Workshops.