Download Worksheet 2 Answer Keys and Notes

J) G(F and L(/III
- anyone of the numbers used in multiplication to
form a product
- the product of a number and an integer (or whole
....Least common multiple
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number)
- the smallest number that is a multiple of two or
more numbers (LCM)
Greatest common factor - the greatest whole number that is a factor of two or
more numbers (GCF)
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Prime factor
- a factor that is a prime number
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Complete eac f.acto. tree. J:hen use the factor tree to write each number as a
product 0 prime factors.
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Write each number as a product of prime factors. Then find the greatest common
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The least common multiple, or LCM, is another number that's useful in solving many math
problems. Let's find the LCMof 30 and 45. One way to find the least common multiple of
two numbers is to first list the prime factors of each number.
30
45
=
=
2 x 3 x 5
3 x 3 x 5
Then multiply each factor the greatest number of times it occurs in either number. If the
same factor occurs more than once in both numbers, you multiply the factor the greatest
number of times it occurs.
Then multiply each factor the greatest number of times it occurs in either number. If the
same factor occurs more than once in both numbers, you multiply the factor the greatest
number of times it occurs.
2: one occurrence
3: two occurrences
5: one occurrence
2 x 3 x 3 x 5 = 90 <- LCM
After you've calculated a least common multiple, always check to be sure your answer can
be divided evenly by both numbers.
3,9, 21
Solution: List the prime factors of each.
3: 3
9: 3 x 3
21: 3 x 7
Multiply each factor the greatest number of times it occurs in any of the numbers. 9 has two
3s, and 21 has one 7, so we multiply 3 two times, and 7 once. This gives us 63, the
smallest number that can be divided evenly by 3, 9, and 21. We check our work by verifying
that 63 can be divided evenly by 3, 9, and 21.
12,80
Solution: List the prime factors of each.
12: 2 x 2 x 3
80: 2 x 2 x 2 x 2 x 5 = 80
Multiply each factor the greatest number of times it occurs in either number. 12 has one 3,
and 80 has four 2's and one 5, so we multiply 2 four times, 3 once, and five once. This gives
us 240, the smallest number that can be divided by both 12 and 80. We check our work by
verifying that 240 can be divided by both 12 and 80.
~ Algebraic Expressions
Equation
- a mathematical sentence with an equal sign (=)
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I have 4
in the fridge and y cases of coke in the basement.
How many cans of coke do I have if 1case has 24 cans'?
Number of ~
Number of
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= 24y + 4
= 24 x 6 + 4 = 148
There are 4 muffins in a bag and k boxes of muffins with 8 muffins in
each box.
a. How many muffins are there?
Number of muffins =
8k f- <f
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b. If there are 7 boxes, how many muffjns are there/?
Number of muffins = rg l1-) -l= 60
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There are 7 apples in a bag and m baskets of apples with 12 apples
if
each basket. How many apples are th~
a. Number of apples = 12m r 7b. If there are 5 baskets, how many ae,P18sare ther)Y?
Number of apples =
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Tony has $3. p of his friends have $5 each.
they have altogether?
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a. Altogether they have: $( C5f·
+ t3
How much money do
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b. If there are 8 friends, how much money do t~y
altogether?
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Altogether they have : $(
l' 56) +
-13 ) ~ $
and
Top1 have
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