Download First Nine Weeks Review

First Nine Weeks Review
JENKINS
Place Value
 Reasons why place value is so important…
 Place value helps us to line up numbers properly so that we are
able to add and subtract correctly.
 Place value helps us to understand if a number is greater than
or less than
 Place value helps us to understand base 10 and the whole on
numeration
Place Value
 Millions,Hundred Thousands, Ten Thousands,
Thousands, Hundreds, Tens, Ones (Decimal) Tenths,
Hundredths, Thousandths, Ten Thousandths,
Hundred Thousandths, Millionths
 7,512,689.1239856
 Do you know the Place values of the underlined
numbers?
Place Value
 > Greater Than
 < Less Than
 = Equal To
 Which of the following sentences is correct?
 A. 9.5 < 4.2
 B. 3.6 > 3.4
 C. 8 = 8.1
Place Value
 The arrow should always point to the least number
  > (greater than) < (less than)
 What sign would you choose to make this sentence
correct?

A. 7 __?__ 10
Adding and Subtracting Fractions
 When adding and subtracting fractions, the
denominators must be the same…

Example: 3/4 + 5/8 =


The denominators are not the same
 Multiply the denominators to make them the same
3/4 (multiply the num and denominator by 6
• 6 * 4 = 24

6 * 3 = 18 )
+5/8 (multiply the num and denominator by 3
• 3 * 8 = 24
3 * 5 = 15)
Adding and Subtracting Fractions Cont.
3/4 = 18/24
+ 5/8
= 15/24
33/24 = 11/8 (lowest terms)
Repeating Decimals
 Repeating decimals will continue on into forever!!!
 Example:
 Example:
0.33333333333
1.23232323232
Terminating Decimals
 Terminating decimals are decimals that end.
 Example: 5.365
After the decimal there are three numbers
 There is no pattern, and it does not continue on
 We are able to turn terminating decimals into fractions
and mixed numbers

Terminating Decimals
 To change a terminating decimal into a fraction you
must know place value.




Example:
Example:
Example:
Example:
0.1 = 1/ 10
3.4 = 3 and 4/10
0.01= 1/100
5.04 = 5 and 4/100
Converting Fractions into Decimals
 Divide the fraction
 The bottom number (denominator) will be your
outside number
 The top number (numerator) will be the inside
number
 Example: ¾ = 4 divided by 3 = .75
Improper Fractions
 When the numerator is greater than the
denominator it is an improper fraction.
 Example: 20/6






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To change an improper fraction into a mixed number divide
the fraction.
6 divided by 20 = 3 r2
The quotient (answer to division) will be your whole number
The remainder will be your new numerator
The divisor (the number you divided by) will be the
denominator
The mixed number will be 3 2/6
3 2/6 = 20/6
Mixed Number
 A mixed number is a whole number and a fraction.
 Example: 3
½
 Convert this mixed number into an improper
fraction by multiplying the denominator and the
whole number then add the numerator
 2*3 =6+1=7
7 is the new numerator
 The denominator stays the same 7/2 = 3 ½
Equivalent Fractions
 Equivalent means EQUAL
 In order to create an equivalent fraction multiply the
numerator and denominator by the same number.

Example: 1/2 If multiplied by 2/2 the equivalent fraction is
2/4
 If you cross multiply equivalent fractions you will get
the same result on each side.


Example: 1/2 = 2/4
2 * 2 = 4 and 1 * 4 = 4
Calculators
 Calculators should only be used as a means to check
your answers.
 To input a fraction to convert it into a decimal: type
the top number, then n then the bottom number, hit
enter, then hit f-> d
 To input a mixed number to convert it into a
decimal: type the whole number, hit unit, then type
the top number, then n then the bottom number, hit
enter, then hit f -> d