Math Rap Rewind 4th Grade TAKS Review
Elapsed time - is the time that passes from the start to the end of an activity. One Way
Another Way
Count forward on a clock.
Count backwards on a clock.
24 hours = 1 day
UseA.M. for times beginning at 12:00 midnight and before12:00 noon
UseP.M. for times beginning at 12:00 noon and before12:00 midnight.
Addition Word Problems Joining groups of different sizes Key words to look for: What is the total? How many in all?
How many altogether? The sum is…
Example: There are 20 students in Mrs. Cain-Heard’s class and 19 in Mr. Cassel’s class. How many students all together are in both classes? 20 + 19 = 39 students
ray
.
point
line
line segment
Steps to finding elapsed time Step 1
Step 2
Count thehours
Count theminutes
7:10 - 10:55
10:10 - 10:55
3 hours (7:10 to 10:10)
45 minutes
Writetheelapsed time3 hours and 45 minutes
Subtraction Word Problems Taking away or comparing groups Key words to look for: How many more? How much change?
How many are left? The difference is…
Example: How many more students are in Mrs. CainHeard’s room than in Mrs. Belrose’s class? 20 – 19 = 1 more student
Bar Graphs Bar Graphs display data so that it can beeasily understood. You can use graphs to comparesets of data.
cak e
cand y
Multiplication Word Problems Joining equal-sized groups Key words to look for: The product is… Find multiples of..
How many altogether? Find the area of…
Example: Mrs. Cain-Heard gave 3 pencils to each of her 20 students. How many pencils altogether did Mrs. Cain-Heard give out? 20 x 3 = 60 pencils
Comparing Money & Percents Percent
Fraction Decimal Fraction Simplified
1 10 10% = .10 = 100 = 10
Transformations Transformations involve moving shapes in different ways.
You can flip shapes (reflection).
You can slide shapes (translation).
You can turn shapes (rotation).
Division Word Problems Finding how many in each group or how
many groups.
Key words to look for: Divide into … parts What are the factors?
How many per? The quotient is…
Example: Mrs. Cain-Heard divided her class of 20 students into 4 equal groups to work on a science project. How many students were in each group? 20 ÷ 4 = 5 students
Degree – a unit of measurement of an angle or arc, represented by the symbol º.
(Right angles are 90º) 90
90º
How do you compare decimals? Use a Number Line Way 1 4.5 is to the left of 4.7, So 4.5 < 4.7
Use a Grid 4.5
4.7
Way 2 Since the model for 4.7 has 20 more shaded squares, 4.5 < 4.7
Use Place Value Ones
Way 3
4 4
. . .
Tenths
Hundredths
5 7
4 = 4 5 < 7 Since 5 is less than 7, 4.5 < 4.7
Digits – numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Place value – tells you how much each digit stands for
Quadrilateral Family
trapezoid
parallelogram
rhombus
rectangle
square
Ones
Thousand
Million
Billion
Trillion
Periods – A group of 3 places used for the digits in large numbers. Periods are usually separated by commas.
684,367,671,690,492
Linear Measurement
(Length)
1 foot 1 inch 1 yard
4 times around track = 1 mile
What is probability? How likely is something going to
happen? What are the chances of an event
happening?
intersecting lines
Place Value - is the value given to the place a digit has in a number. Numbers are made up of digits in the same way that words are made up of letters. A place-value chart can help explain what this number means.
Thousands
Ones
tens
ones
3
1
The value of the 3 is 30,000.
The value of the 1 is 1,000.
hundreds
tens
ones
5
4
2
The value of the 5 is 500.
The value of the 4 is 40.
The value of the 2 is 2.
,
Therearedifferent ways to write31,542 You can usestandard form.
31,542
You can useexpanded form.
30,000 + 1,000 + 500 + 40 + 2
You can useword form.
thirty-onethousand, fivehundred forty-two
Probability Vocabulary We use the following words to describe the likelihood or chance of something happening: IMPOSSIBLE (It will never happen!!) UNLIKELY (It may happen but probably won’t) LIKELY (It may happen and probably will) CERTAIN (It will definitely happen)
Use Rounding • When the question asks you to estimate. • When the question asks “about how many”…? • When an exact answer isn’t possible. • When an answer is difficult to obtain.
1 meter
1 millimeter
1 centimeter
x 100
1 kilometer
Memorize this Poem for Rounding
Four or less, let it rest Five or more, raise the score
Angle – two rays that meet at a common end point.
Estimating Words we use when we are estimating.
o t e
C
s o l
Ne ar ly
About how many
Comparing Money & Percents Percent
Fraction Decimal Fraction Simplified
1 50 50% = .50 = 100 = 2
(Right angles are 90º) 90
90º
right angle (What Ever Loser Right Angle)
Weight Measurement Benchmarks
A slice of bread weighs about 1 ounce
A loaf of bread weighs about 1 pound
A car weighs about 1 ton
Comparing Money & Percents Percent
Fraction Decimal Fraction Simplified
1 25 25% = .25 = 100 = 4
Capacity Measurement Benchmarks A cup of milk
A quart of milk
A measuring cup
A pint of milk The size of milk you get at lunch
A gallon of milk
Quadrilateral – a polygon with 4 angles and 4 straight sides.
(Obtuse angles are more than 90º) 90
130º
obtuse angle (Call Me Obtuse)
Equivalent fractions name the same amount of a set or region. Example:
So, 2/8 and 1/4 arecalled equivalent fractions becausethey namethesameamount. You can usedrawings to find equivalent fractions. Thefirst circleis divided into 2 parts and represents 1/2. Thesecond circleis divided into 4 parts and represents 2/4. Fractions that namethe sameamount arecalled equivalent.
=
=
Addition/Subtraction Fact Families are found by: Starting with a simple addition fact.
( 2 + 5 = 7) Changing the addends around.
(5 + 2 = 7) Writing the Inverse operations for both.
(7 - 2 = 5
& 7 - 5 = 2)
Right angle #1
Right angle #2
Right angle #3
Right angle #4
perpendicular lines (Perpendicular lines make four right angles)
Ordering Numbers to 10,000. You can use base-ten blocks. Order the numbers 274, 276, and 239 from least to greatest. Compare the value of the blocks in each place value position from left to right. Keep comparing until they are different.
Number
Hundreds
Tens
Ones
There are the same number of hundreds.
3 is less than 7 So, 239 is the least number.
4 is less than 6 So, 276 is the greatest number.
274
276
239
Answer
In order from least to greatest: 239 ; 274 ; 276
(Acute angles are less than 90º) 90
50º
acute angle (Peace Out Acute)
Volume Measurement Benchmarks A milliliter About a drop of liquid
A liter The size of a large water bottle
Multiplication/Division Fact Families are found by: Starting with a simple multiplication fact.
( 3 x 9 = 27) Changing the factors around.
(9 x 3 = 27) Writing the Inverse operations for both.
(27 ÷ 3 = 9 & 27 ÷ 9 = 3)
Area is the number of square units needed to cover a flat surface. Some Metric Units for measuring area are square centimeter, square decimeter, or square meter. Find the area of a figure by counting the shaded squares or multiply the length times the width. 1 square unit = 6 square cm
2
3x2=6
3 Sometimes you need to count half squares to find the area of a figure.
1 whole square + 2 half squares 2 half squares = 1 whole square 1 + 1 = 2 square units
Sometimes you need to estimate the area of a figure.
4 whole squares + 4 almost whole squares + 4 about half squares 4 half squares = 2 whole squares 4 + 4 + 2 = about 10 square units
Hint : The"mouth" of either sign always opens towards theGREATER NUMBER.
58 13
54 23
Rules for Converting Units How many inches are in 4 feet? To change from a larger unit of length to a smaller unit of length, multiply .
4 feet = ___ inches Think: 1 ft = 12 inches 4 x 12 = 48 4 feet = 48 inches How many yards are in 18 feet? To change from a smaller unit of length to a larger unit of length, divide .
18 feet = ___ yards Think: 3 ft = 1 yd 18 divided by 3 = 6 18 feet = 6 yards
parallel lines These lines will never touch each other.
Mass Measurement Benchmarks A gram A paper clip weighs about 1 gram
A kilogram A text book weighs about 1 kilogram
Here are som e ways to divide a whole into equal parts.
halves
thirds
fourths
fifths
sixths
eighths
tenths
twelfths
Fractions are located on number lines.
3D shapes A pyramid has a 2D shape for a base and triangular sides that join in a point. So a square-based pyramid has a square base. A prism has a cross-section that is a 2D shape. It has the same crosssection all along its length. So the cross-section of a triangular prism is a triangle. vertex (vertices)
face
side (edges)