**TEST ON THURSDAY, OCTOBER 30, 2014**
Module 1 Study Guide
When you x, the number gets bigger.
Multiply
And
Divide
Decimals
With
Exponents
a) 3.5 x 103 =
103 = 1000
so number gets
bigger by 3 place
values
3
5
0 0
3
5
Multiply
When you ÷, the number gets smaller.
b) 3.5 ÷ 102 =
3
0
2 =
10 100 so
number gets
smaller by 2
place value
5
0
3
5
Divide
*How are these two problems and answers the same?
Both problems began with 3.5 and for both problems, the numbers
moved on the place value chart.
*How are these two answers different?
In the multiplication problem, the number moved to the left 3 places
and in the division problem, the number moved to the right 2 places. In
the multiplication problem, the value of the number got larger and in the
division problem, the value of the number got smaller.
Fill in <, >, or = in the circle. Under each problem, explain with place
values how you knew the answer. Don’t forget to line up the decimals.
0.49
<
0.675
Explanation: When I lined up the decimals, the 6 in the tenths place is
smaller than the 4 in the tenths place.
8 tenths + 2 tenths + 7 hundredths
(0.827)
Comparing
Decimals
In
Different
Forms
<
1.23
Explanation: When I lined up the decimals, the 1 in the ones place is
bigger than the 0 in the ones place.
12.745
<
12.760
Explanation: When I lined up the decimals, the 6 in the hundredths place is
bigger than the 4 in the hundredths place.
(6 x 1000) + (2 x 100)
(6, 200)
>
(4 x 100) + (9 x 10)
(490)
Explanation: When I lined up the numbers, there is a 6 in the thousands
place in
6,200 and there is no number in the thousands place in 490 so
6,200 is bigger than 490.
Standard Form:
(just numbers)
23. 4
Different
Forms
Word Form:
(write numbers and place values in words)
23. 4 = Twenty Three AND Four Tenths
Expanded Form:
(write the number first then multiply the place value it is in)
( 2
x 10 ) + ( 3 x
1 ) + ( 4
x 0.1 ) = 23. 4
OR
( 2
x 10 ) + ( 3 x
1 ) + ( 4 x 1/10 ) = 23. 4
Subtract:
68.17 – 23.46 = set up the problem
-
Subtracting
Decimals
7 11
6 8. 1 7
2 3. 4 6
4 4.7 1
Don’t forget to line up the decimals.
Round 10.379 to the nearest tenth. (10.379)
Rounding
to the
nearest
Tenth and
Whole
Number
10.4
10.37 (7 tells us to round up)
10.35
10.3
Round 7.5 to the nearest whole number (ones)
(7.5)
8
7.5
7.5 (5 tells us to round up)
7
What is the total of these two numbers?
*When you see total, it means to ADD (+)
Don’t forget to line up the decimals.
Adding
Decimals
+
1
1 0. 3 7 9
7. 5 0 6
1 7 . 8 8 5
Division Problem:
10.45 divided by 5
Steps to Long Division
Does
McDonald’s
Long
Division
and
Dividing
Decimals
Sell
Cheese
Burgers
2 . 0 9
5 1 0 . 4 5
-1 0
0 4
0
4
5
4
5
0
D = Divide
÷
M = Multiply x
S = Subtract
-
C = Check
B = Bring Down