Download Adding Integers - White Plains Public Schools

MATH REVIEW UNIT 2
DATE: _________
Name ______________
How do we multiply fractions?
1st multiply the numerators
2nd multiply the denominators
3rd write the answer in simplest form
1st
3rd
2 5 2  5 10 5
 


3 8 3  8 24 12
2nd
Shortcut- Cancelling
Simplify the factors before multiplying.
2 5 1 5 5
 

3 8 3  4 12
2 is a factor of 2 and 8.
2÷2=1 8÷2=4
Practice:
1)
1 8
  ______
4 9
2) 6 
3
 ______
4
1 1
3) 10  1  ______
2 3
How do we divide fractions?
1st- Rewrite the problem as a multiplication
problem. Use the reciprocal of the divisor
as the second factor.
nd
2 multiply the fractions as usual.
3rd write the quotient in simplest form
Divide:
3
6
4
3 1
3 1
 

4 6 24 8
rewrite
Divide:
rewrite
3 6

4 1
3 2

4 3
3 3 9
1
  1
4 2 8
8
Practice:
4)
7 1
  ______
8 4
5)
7
 4  ______
8
6)
1 2
  ______
3 9
**Remember
When you divide a larger number by a smaller number, the quotient is greater than 1.
When you divide a smaller number by a larger number, the quotient is less than 1.
How do we multiply decimals?
1st – Multiply like whole numbers.(you do not
have to line up the decimal points.)
2nd – Count all the places to the right of the
decimal point in each factor. Count the same
number of places in the product and write
the decimal point.

You may have to write some zeros as
place holders in order to put the
decimal point in the correct place in
the product.
Problem
Multiply:
1st
6.82
X 4.3
2046
+27280
29326
Multiply:
6.82 •
Factor
4.3 =
Factor
Product
2nd
6.82 2 places
X 4.3 1 places
2046
+27280
29.326 3 places
0.24 •
Factor
0.3 =
Factor
0.24
X 0.3
0.072
Practice: 7) 2.6 • 4 = ______
29.326
8) 32.5(0.7)  _______
0.072
Product
2 places
1 places
3 places
9) 5.6 • 0.53 = _______
How do we divide decimals?
1st - To divide a decimal by another decimal,
REWRITE the problem so that the divisor is
a whole number. Move the decimal to the
back
2nd – move the decimal the same amount of
places in the dividend, and then place the
decimal point up in the quotient.
3rd – NOW divide
4th – write the answer
Practice: 10)
13.63
= ______
2.9
Problem
Divide: 201.24
Dividend
÷
4.3
Divisor
= 46.8
Quotient
1st 43 201.24 2nd 43 2012.4
rd
3
46.8
43 2012.4
4th answer: 46.8
-172
292
-258
344
-344
0
11) 1.3 0.65  _______
12) 0.476 ÷ 0.007 = _______
2.11 practice and homework
2)Ally withdrew $105.25 from her checking account for 4 months. What was the
total change to her account after the 4 months?
Show work
Answer: __________
Math sentence: __________________________________
6) Find the perimeter and the area
2
3
9 ft.
5
6
3 ft.
Show work!
Perimeter = ___________________
Area = ____________________
Part E: Divide signed decimals
Solve this problem:
-3.148 ÷ 0.04
Answer: ______________
1)
On the lines below, explain very clearly, how you solved this problem
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
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Part F:
Converting fractions to decimals
a) Convert
2)
4
5
to a fraction.
On the lines below, explain very clearly, how you solved this problem
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
___________________________________________________________________
What type of decimal is
4
?
5
______________________