Post on 01-Apr-2015
Dividing by Whole Numbers
Lesson 3-8
In long division, we use both multiplication and division.
Key Vocabulary…
) dividenddivisor
quotient
Parts of a division problem…
GOES INTO
DIVIDED
BY
To keep your long division steps in order,
remember the basic family…• DAD
– Divide the divisor into the dividend• MOM
– Multiply the divisor by the factor you are about to put into your quotient
• SISTER– Subtract the product from the
dividend/difference• BROTHER
– Bring down the next digit in your problem• Rover
– Repeat or remainder
Writing the Division Problem…
When you are thinking about lunch… I mean long division… think of In-and-Out.
Example 1
Divide as with whole numbers but when I meet the decimal point in the dividend I add it in the quotient!!
4.264
6.6
-242424
0
-
Example 1
Check your answer. Multiply the quotient
by the divisor.
Your answer should be the dividend.
6.6
X 4
26.4
What do I do if I have zeroes in my problem?
) 1402.527Does 7 go into 14?
Yes. 2 times. Put the 2 over the 4 (my last
underlined number)
2 7 x 2 = 14
-140
Subtract 14-14= 0
) 1402.527Does 7 go into 0 or
00?
No. Put the 0 in the quotient over the 0 in the dividend.
2 7 x 0 = 0
-140 Bring down
the zero0
0
00
0 – 0 = 0
) 1402.527
Does 7 go into 2?
No. Put the 0 in the quotient
over the 2.
2 7 x 0 = 0
-140 Bring down
the 20
0
002
0
2 – 0 = 2
02
) 1402.5272
-1400
0
002
0
0 2
Send up the
decimal point.
) 1402.527
Yes. 7 x 3 = 21. Put the 3 in the
quotient over the 5.
27 x 3 = 21
-140
Bring down the 5
0
0
002
0
25 – 21 = 4
0 2
Does 7 go into 25?
521
4
3
) 1402.527
Yes. 7 x 6 = 42. Put the 6 in the
quotient over the 2.
27 x 6 = 42
-140
Bring down the 2
0
0
002
0
42 – 42 = 0
0 25
Does 7 go into 42? 2
42
4
63
21 0
) 1402.527200 63
And the answer is…
Let’s Practice…
Now try these two.
6.85242.8
05.1352.61
How did you do?
Let’s try rounding to the nearest 10th.
1. Look at the number to the right of the number in the 10ths place.
2. If it is 0, 1, 2, 3, or 4, round down.
3. If it is 5, 6, 7, 8, or 9, round up.
4. .925 rounds to .9
.925 .9
3.467 3.5
26.45 26.5
4.01 4
325.23 325.2
Practice
Try 1) 25.2÷4=
Answer:
Did you get it 6.3?
Try 2) 65.28÷12= hint: round to the nearest tenth first!!
Answer: Did you get it 5.44?
) 108.54618.09
) 1661.8811151.08
• Thanks for attending