| Watch Video on Lowest Common Denominator - Pre Algebra Help |
 |
Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/leastco
mmondenominator.php Students learn to add
unlike fractions by first finding a common
denominator. For example, to add 1/2 + 1/3,
first find the common denominator of 2 and 3,
or the Least Common Multiple of 2 and 3,
which is 6. Then multiply the numerator and
denominator of 1/2 by 3, to get the
equivalent fraction 3/6, and multiply the
numerator and denominator of 1/3 by 2, to get
the equivalent fraction 2/6. Next, add the
like fractions, 3/6 + 2/6, to get 5/6. So 1/2
+ 1/3 = 5/6. Students also learn to subtract
unlike fractions by following the same
process that is used when adding unlike
fractions.
Tags : adding subtracting fraction fractions addition subtraction unlike denominator denominators least |
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Affichage : 6586
Durée : 78 s |
| Watch Video on Dividing Decimals - Pre Algebra Help |
 |
Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/dividin
gdecimals.php Students learn to divide a
decimal by a decimal by first multiplying
both decimals by the power of 10 that changes
the second decimal to a whole number. For
example, to divide 0.16 by 0.8, first
multiply both decimals by 10, to get 1.6 8.
Next, divide the decimal by the whole number
in the same way that one would divide a whole
number by a whole number (using long
division). However, at the end of the
problem, the decimal point is brought
straight up from the decimal that is inside
the division symbol to the answer that is
written on top of the division symbol.
Tags : dividing decimal by numbers division long divide |
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Affichage : 10059
Durée : 102 s |
| Watch Video on Dividing Mixed Numbers - Pre Algebra Help |
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Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/dividin
gmixednumbers.php Students learn to divide
mixed numbers by first rewriting the mixed
numbers as improper fractions, then dividing
the improper fractions, then rewriting the
resulting improper fraction as a mixed
number, if necessary. For example, to
simplify 3 1/3 1 4/7, first rewrite the mixed
numbers as improper fractions, to get 10/3
11/7. Next, change the division sign to
multiplication and flip the second fraction,
to get 10/3 x 7/11. Next, multiply across the
numerators and denominators to get 70/33.
Finally, rewrite 70/33 as the mixed number 2
4/33.
Tags : dividing mixed number numbers division fraction fractions divide |
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Affichage : 7719
Durée : 124 s |
| Watch Video on Customary Unit Conversions - Pre Algebra Help |
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Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/customa
ryunitconversion.php Students learn the
following customary units of measurement:
inch, foot, ounce, ton, fluid ounce, pint,
gallon, yard, pound, cup, quart, and so on.
Students also learn to convert from one
customary unit of measurement to another
using the following conversion factors: 60
seconds = 1 minute, 7 days = 1 week, 3 feet =
1 yard, 16 ounces = 1 pound, 4 quarts = 1
gallon, and so on. Students are then asked to
solve problems using conversion factors, such
as 18 feet = ____ inches.
Tags : unit conversion measurement measure weight problem customary units |
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Affichage : 3197
Durée : 106 s |
| Watch Video on Least Common Multiple - Pre Algebra Help |
 |
Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/leastco
mmonmultiple.php Students learn that
multiples of a number come from multiplying
the given number by whole numbers. For
example, 3 x 0 = 0, 3 x 1 = 3, 3 x 2 = 6, 3 x
3 = 9, 3 x 4 = 12, 3 x 5 = 15, etc., so 0, 3,
6, 9, 12, and 15 are all multiples of 3.
Students also learn that the Least Common
Multiple is the smallest multiple that two
numbers have in common (not including zero).
For example, to find the Least Common
Multiple of 6 and 18, since multiples of 6
are 6, 12, 18, 24, and 30, etc., and
multiples of 18 are 18, 36, 54, etc., the
Least Common Multiple of 6 and 18 is 18.
Tags : least common mutiple multiples LCM finding find problem problems math |
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Affichage : 3333
Durée : 115 s |
| Watch Video on Multiplying Decimals - Pre Algebra Help |
 |
Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/multipl
yingdecimals.php Students learn to multiply
decimals in the same way that one would
multiply whole numbers (vertically). However,
at the end of the problem, students must
determine where the decimal goes in the
answer by counting the total number of digits
to the right of the decimal point in the
original numbers, then placing the decimal
point in the answer so that the answer has
this same total number of digits to the right
of the decimal point. For example, after
multiplying 1.05 x 7.4, since there are a
total of 3 digits to the right of the decimal
point in the original numbers, place the
decimal point in the answer so that there are
3 digits to the right of the decimal point.
Tags : multiplying decimal decimals multiplication multiply by |
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Affichage : 2441
Durée : 132 s |
| Watch Video on Dividing Fractions - Pre Algebra Help |
 |
Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/dividin
gfractions.php Students learn to divide
fractions by first changing the division sign
to multiplication and flipping the second
fraction. For example, to simplify 7/12
divided by 7/9, first change the division
sign to multiplication and flip the second
fraction, to get 7/12 x 9/7. Next, multiply
the fractions by first cross-canceling, then
multiplying across the numerators and across
the denominators.
Tags : dividing fraction fractions division divide help example |
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Affichage : 4802
Durée : 75 s |
| Watch Video on Subtracting Mixed Numbers - Pre Algebra Help |
 |
Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/subtrac
tingmixednumbers.php Students learn to
subtract mixed numbers by first subtracting
the fractions, then subtracting the whole
numbers. For example, to subtract 6 1/3 - 4
2/3, first subtract 1/3 � 2/3. However,
notice that 1/3 � 2/3 equals a negative
fraction. In this situation, the first
fraction, 6 1/3, can be rewritten as 5 + 1
1/3, or 5 + 4/3, or 5 4/3. Therefore, the
original problem, 6 1/3 - 4 2/3, can be
rewritten as 5 4/3 - 4 2/3. Now, subtract
the fractions, 4/3 � 2/3, to get 2/3,
and subtract the whole numbers, 5 �4, to
get 1. So 5 4/3 - 4 2/3 = 1 2/3. Note that
some of the problems in this lesson also
require the student to find a common
denominator for the fractions. For example,
8 5/16 - 1 1/8.
Tags : subtracting mixed numbers fractions subtract subtraction math |
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Affichage : 4204
Durée : 95 s |
| Watch Video on Subtracting Whole Numbers - Pre Algebra Help |
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Access full lesson containing this video at:
http://www.yourteacher.com/prealgebra/subtrac
tingwholenumbers.php Students learn to
subtract numbers with two or more digits,
such as 985 - 47. The first step is to line
up the numbers vertically so that the units
digits are in the same column. Next, subtract
the units digits, the tens digits, and the
hundreds digits. When subtracting the units
digits, notice that it is not possible to
subtract 7 ones from 5 ones, so 1 ten must be
borrowed from the tens column, leaving 7 tens
and 15 ones. Now, subtracting the units
digits, 15 - 7 = 8, subtracting the tens
digits, 7 - 4 = 3, and subtracting the
hundreds digits, 9 - 0 = 9. So 985 - 47 =
938. Note that the answer to a subtraction
problem is called the difference, so the
difference of 985 - 47 is 938.
Tags : Subtracting Whole Numbers 2-Digit subtract subtraction two digit number two-digit math three |
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Affichage : 802
Durée : 85 s |
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