Where Are We Now?. We have learned how to: compare and order decimals. estimate by rounding and using compatible numbers. solve equations containing decimals. write numbers in scientific notation. Where Are We Going?. We will: use divisibility rules.
6.5.3:use number theory concepts of primes, factors, multiples, and rules of divisibility to show number relationships
Least Common Multiple
A multiple of a number is the product of the number and a whole number.
The first five non-zero multiples of 5 are: 5, 10, 15, 20, 25.
We have seen that numbers can have common factors. They also have common multiples.
List the multiples of 4:
List the multiples of 6:
Common multiples of 4 and 6 include 12 and 24. The LCM is ____________.
Don’t list too many multiples of one number before beginning the other list. You may write many more than you need
Find the LCM of 8 and 10.
8: 8, 16, 24, 32, 40, 48, 56
10: 10, 20, 30, 40, 50
LCM = __________________
In one part of a musical composition, the triangle player in an orchestra plays once every 12 beats. The tympani player plays once every 9 beats. How often do they play together?
(Hint: You need to find the LCM of 12 and 9.)
A Problem for You
A local restaurant is offering a free meal to every 25th customer on Valentine’s Day and a bouquet of roses to every 12th customer. Which customer will be the first to get both a free meal and a free bouquet?
Happy Valentine’s Day
To ALL of my Sweethearts!