becky afghani, lbusd math curriculum office, 2003 snack problem! serena wants to create snack bags...
Post on 17-Dec-2015
216 Views
Preview:
TRANSCRIPT
Becky Afghani, LBUSD Math Curriculum Office, 2003
Snack Problem!Serena wants to create snack bags for a trip she is going on. She has 6 granola and 10 pieces of fruit.
If the snack bags should be identical without any food left over, what is the greatest amount of snack bags Serena can make?
Cookout Problem!Hot dogs come in
packages of 8. Hot dog buns come in packages of 12. Grace wants to have an equal amount of buns and hot dogs so that every bun has a hot dog.
What is the least amount of packs of each that will she need to buy so she has no buns or hot dogs left over?How are the two problems similar?
How are the two problems different?
The Listing Method
For Finding LCM
MCC6.NS.4: Find the greatest common factor of two
whole numbers less than or equal to 100 and
the least common multiple of two whole numbers
less than or equal to 12.
Becky Afghani, LBUSD Math Curriculum Office, 2003
What are multiples?Multiples are defined as the product of a number and any whole number.
Becky Afghani, LBUSD Math Curriculum Office, 2003
What is meant by smallest common multiple or LCM?
The LCM is the smallest multiple that two or more numbers have in common.
The LCMof 6 and 16
is 48.
Becky Afghani, LBUSD Math Curriculum Office, 2003
Cookout Problem!Hot dogs come in packages of 8. Hot
dog buns come in packages of 12. Grace wants to have an equal amount of buns and hot dogs so that every bun
has a hot dog. What is the least amount of packs of each that will she need to buy so she has no buns or hot
dogs left over?
The Ladder Method
For Finding LCM
Becky Afghani, LBUSD Math Curriculum Office, 2003
Let’s find the Least Common Multiple (LCM) of
28 and 70The LCM is the product of all the
numbers on the left and the bottom.
The LCMof
28 and 70is 140.
2x7x2x5 = 140
Becky Afghani, LBUSD Math Curriculum Office, 2003
Which numbers in the ladder give you the LCM?
The “L” shape gives you the LCM: multiply the numbers
on the left and bottom.
Becky Afghani, LBUSD Math Curriculum Office, 2003
Let’s try some bigger numbers.
Divide out all the common factors down the left side.
What numbergoes into both
24 and 60?Does any #
besides 1go into both 12 and 30?How about6 and 15?
Anything else?No?
You’re done.
Becky Afghani, LBUSD Math Curriculum Office, 2003
x
x
xx
Find the LCM.
=120
The LCMof
24 and 60is 120.
Becky Afghani, LBUSD Math Curriculum Office, 2003
x
x
Find the GCF.
=12
The GCFof
24 and 60is 12.
Becky Afghani, LBUSD Math Curriculum Office, 2003
Practice. Find the LCM Practice. Find the LCM
for 28 and 42. for 28 and 42.
LCM = 2 7 2 3 = 84
Becky Afghani, LBUSD Math Curriculum Office, 2003
Practice. Find the GCF for Practice. Find the GCF for
28 and 42. 28 and 42.
GCF = 2 7 = 14
top related