Download Math Review - Galena Park ISD Moodle

Math Review
Cheers and Songs
Place Value
To the left, to the left multiply by 10 (place value gets bigger)
Ex: hundreds place is 10 times bigger than ones place 70x10=700 (1,774)
To the right, to the right, find 1 tenth (place value gets smaller)
Ex: ones place is one-tenth of the tens place
50/10=5 (2,455)
Karl Roemer’s Place Value song
Ones period
O/T/H
Thousand period
Th / TTh / HTh
Million period
M / TM / HM
Billion period
B / TB / HB
What’s my decimal? O . Tth Hth
9/10=__ 3/100=__ 5/10=_
_ 83/100=__
The digit in the ones place of the numerator belongs in the demoninator’s place
value. 34/100 = 4 is in the one’s place of the numerator so it belongs in the
hundredths place as a decimal.
What is my fraction? The place value that the last digit is in will be
the denominator.
0.45=__
0.3=__
0.53=__ 0.7=__
Rounding numbers
Round to the place value:
Go to the place
Look next door,
If it’s 5 or bigger, yes, add one more OR No, don’t add more.
Numbers on the right, zero is the name.
Numbers on the left, stay the same.
Round to the hundred’s place:
3958
2836
1778
Reasonable Rounding:
Round to the nearest 100
175 is closer to 200 than it is to 100, so it will round to 200.
340
769
230
888
782
489
923
Comparing, adding or Subtracting
decimals
When comparing, adding or subtracting decimals, line up
the decimals then add a zero where needed.
3.68
3.20
3.17
2.90
4.70
+ 3.89
5.60
-3.75
Properties of Multiplication
Commutative property-You can change the order
of factors but the product remains the same.
Associative property-You can change the
grouping of factors from here to here but the
product remains the same.
Identity property-when you multiply any number
by 1, the product is that number.
Zero property-when you multiply any number by
zero, the product is zero.
Distributive property-product is found by breaking
one factor into ones, tens, hundreds, then
multiplying each of these by the other factor.
Multiplying two 2-digit numbers
Step 1
ones time ones
Step 2
ones time tens
Put a zero in the ones place to multiply by 10(underline the digit in the ten’s
place)
Step 3
tens time ones
Step 4
tens time tens
Add the products to get your answer
53
X 24
X 42
73
X 93
82
Long Division
Karl Roemer’s Long Division Song
Divide :
Multiply X
Subtract Bring Down
Fractions
Way down deep in the denominator (repeat)
The whole is divided (repeat)
(numerator ¾ denominator)
Way up north in the numerator (repeat)
The parts are numbered (repeat)
Improper Fraction is when the top is bigger than the bottom
denominator)
(the numerator is bigger than the denominator)
(numerator 9/2
Mixed Number is a whole number and a fraction,
It’s a whole number and a fraction.
4½
Decompose Fractions
6/12 = 1/12+1/12+1/12+1/12+1/12+1/12
8/10 = 4/10+4/10
or
2/10+2/10+2/10+2/10
1/12, 4/10, and 2/10 are called unit fractions
Comparing Fractions
When comparing fractions with
the same numerators:
If the numerators are the same,
the smaller the denominator,
the bigger the fraction.
½ > ¼
When comparing fractions with the same
denominators:
If the denominators are the same,
the bigger the numerator,
the bigger the fraction.
¾ > ¼
If both numerators and
denominators are different:
find the common denominator by
multiplying or dividing.
Remember: What you do to the top, you must do to the
bottom!
2 x (¾) = 6/8
>
⅝
Butterfly It!
To check your fraction comparison,
Butterfly it by:
multiplying the denominators by the
numerator of the opposite fraction.
Remember to multiply from the denominator across to the
numerator.
Comparing Fractions
Common denominator
⅗< ⅘
⅞>⅝
Different denominator
Find the common denominator by multiplying numerator and denominator by
the same number
4/8 > < = 1/4 (4x2=8 & 1x2=2) ⅗ < > = 2/3
⅗ x3=9/15 ⅔ x5 =10/15
2/5 < > = 3/6
7/8 < > = 9/10
Cross multiply denominator (x) numerator
When the denominators are the same, the bigger the numerator, the bigger the fraction.
When the numerators are the same, the bigger the denominator, the smaller the fraction
When all of the digits are different, find a common denominator by multiplying or dividing remembering that what you do
to the top, you do to the bottom.
Reasonableness of fractions
_______1________1________3_______
0
4
2
4
1
What is the nearest fraction?
2/4
⅞
⅖
4/6
2/9
Fractions of a number line
Figure out how the number is divided up
between the whole numbers. Then label the
number line to make sure you are correct.
I_ _I___I___I___I___I___I___I___I___I___I
1
1.1
1.4
1.8
2.0
Patterns
Find the rule then complete the table.
The Rule is: __________________________
Lines
Parallel lines = 2 lines that never cross
Perpendicular lines = 2 lines that cross and
form a 90 degree angle
Intersecting lines = 2 lines that cross and
form 2 acute angles and 2 obtuse angles
Lines
What is a parallel? (stomp, clap, clap, stomp)
This is a parallel. (stomp, clap, clap, stomp)
What is intersecting? (stomp, clap, clap, stomp)
This is intersection. (stomp, clap, clap, stomp)
What is perpendicular, don’t forget right angle?
(stomp, clap, clap, stomp)
This is perpendicular, with a right angle.
(stomp, clap, clap, stomp)
What’s a line of symmetry? (stomp, clap, clap, stomp)
This is a line of symmetry. (stomp, clap, clap, stomp)
Angles
Angles, angles, we need to know about angles,
Acute, acute, smaller than a corner.
Obtuse, obtuse, bigger than a corner.
Right, right, right is a corner with a 90 degree angle, with a
90 degree angle.
Geometry words
Endpoint- dot on a line
Line- a line that goes on and on in 2 directions
Line segment- a line with 2 endpoints
Ray- a line with an endpoint and goes on & on in 1 direction.
Parallel lines- 2 lines that never touch
Perpendicular lines- 2 lines that cross with a 90 degree angle
Intersecting lines- 2 lines that cross and have 2 acute angles and 2
obtuse angles.
Angle-2 rays with a common endpoint
Acute angle- less than 90 degrees
Obtuse angle- greater than 90 degrees
Right is 90 degrees
Measurement of angles
360 degrees
180 degrees
90 degrees
45 degrees
30 degrees
60 degrees
Quadrilaterals
Parallelogram has 2 pairs of parallel sides.
Rectangle has 4 right angles and 2 pairs of parallel sides.
Square has 4 right angles and all sides are the same.
rhombus is a quadrilateral with opposite sides that are parallel and all
of its sides are congruent (the same size, same shape).
trapezoid is a quadrilateral with only one pair of parallel sides.
Triangles
Triangles classified by sides
Equilateral = 3 equal sides
Isosceles = 2 equal sides
Scalene = 0 equal sides
Triangles classified by angles
Right triangle = one right angle
Acute triangle = 3 acute angles
Obtuse triangle = one obtuse angle
Morning Review Problems
1.
2.
3.
I
Number of the Day is ____________________ Complete the chart in tool box.
Write the place value chart from Billions to Hundredths.
Complete the number line:
I
I
I
I
I
I
I
I
I
4.
Convert these decimals into fractions.
__________
__________
5.
6.
7.
Convert these fractions into decimals.
__________
__________
__________
__________
__________
Multiply these 2 numbers by the powers of ten up to X 10,000.
__________
__________
Solve these 2 multiplication problems.
8.
Solve these 2 division problems.
9.
Word Problem for the day.
__________
I