mr. gifford’s math lesson #20 dividing 1 digit by 2 digit numbers
TRANSCRIPT
Mr. Gifford’s Math
Lesson #20
Dividing 1 digit by 2 digit numbers
As we said before in the previous lesson
Division is breaking down a
number into smaller equal groups.1
05 5You can break down the number 10 into 2 equal
groups of 5.
There are 2 symbols for division. One is what is called the HOUSE.
10
5
The second symbol is this
..10
5
Division is not hard at all. Just keep in mind
that Division is the opposite of
Multiplication. So, if you know your Multiplication facts then division should not be hard at all.
Now lets break down some numbers.
20
4
First ask yourself how many times can 4 go into the number 2.
Since 4 goes into 2, 0 times a 0 is placed above
the digit 2.
20
4
Next, ask yourself how many times 4 goes
into 20.
0
Since 4 goes into 20, 5 times a 5 is placed above
the digit 0.
20
4
So, your answer is 5.
05
Now lets work on a larger number .
A good way to remember how
division works is to say
Divide
Bring Down
MultiplySubtract
48
4
First Divide – How many times does 4 go into 4?
The answer is 1
1
48
4
Now multiply4 x 1 = 4.
Place the 4 under the digit 4.
1X
4
48
4
Next subtract4-4=0.
Bring down the 8.
1
408
48
4
Nextask yourself how many times does 4 go into 8
The answer is 2. Place the 2 above the digit 8.
1
408
2
48
4
Now multiply2 x 4 = 8. Place the 8 under the digit 8.
Subtract 8 from 8 to get 0.
1
408
2
80
X
48
4
Your answer is 12To check to see if your answer is correct multiply 12 x 4= 48. 48 matches the Dividend 48. So the answer is correct.
12
408
Now what happens if your answer does not divide your number EVENLY and there is a number left over?
Lets find out.
38
7First ask yourself howmany times does 7 go into 3? 0 times. Place 0 above the digit 3.
0
Multiply 0 x 7 and place the answer 0 under the digit 3.
0
38
7Subtract 3-0=3, then bring down the 8.
0
Now ask yourself how many times does 7 go into 38?
038
38
7Subtract 3-0=3, then bring down the 8.
0
Now ask yourself how many times does 7 go into 38?
038
38
7
Well, since you know 7x5=35 that is as close as you can get.
0
Place 5 above the digit 8.
038
5
Multiply 5 x 7 = 35 and place the 35 under the number 38.
35
38
7
Now subtract 38-35=3. 0
038
5
353
Since 7 can not go into 3 you will have a remainder of 3.
R3
38
7
To check the problem multiply 5x7=35. Then add the remainder of 3 + 35 and you get 38. If this answer matches your dividend then you are correct.
0
038
5
353
R3
Lets try 3 digit dividends. This is not any different from 2
digits except that you have to continue to work out the problems a few
extra place values.
234
4
Ask yourself how many times 4 goes into 2
It goes 0 times. Place the 0 above the digit 2.
0
234
40Multiply 0 x 4
= 0. Place the 0 under the digit 2
0
Subtract 2-0=2
2
Bring down the digit 3 to make 23.
3
234
40How may
times does 4 go into 23 0Think of your times tables and you will know that 4x5=20. That is close to 23.
2320
5
234
40Subtract 23-
20=3
02320
5
3
Bring down the digit 4
4How many times does 4 go into 34
234
40Think of your
times tables and you know that 4x8=32. So 32 is close to 34.
02320
5
34Place the 8 above the digit 4
8
234
40Multiply
8x4=32. Place the 32 under the 34.
02320
5
34
8
32
Subtract 34-32=2
2
4 can not go into 2, so 2 is your remainder. Place the 2 up with an R =remainder.
R 2
2344
To check the problem multiply 58x4=232. Then add the remainder of 2 + 232 and you get 234. If this answer matches your dividend then you are correct.
0
023
5
2034
R2
322
8
So that is division. The quick and short of it. Now it is up to you to practice.
Use the attached page to practice what you have
learned.
Good Job and good Luck!