Math 6A (Periods 2 & 4)

Writing Inequalities 2-3

2 < 7 and 7 > 2 are two inequalities that state the relationship between the numbers 2 and 7

2 < 7 reads 2 is the less than 7 and
7 > 2 reads 7 is greater than 2
The symbols < and > are called inequality symbols.

Notice the mathematical sentence (inequality)
Two is less than ten or 2 < 10 is different from the mathematical phrase (expression)
Two less than ten. 10 - 2
A number 2 + x is greater than a number t 2 + x > t

The point of the number line that is paired with a number is called the graph of that number.

Check out the graph in the middle of page 39 of our textbook. When you graph numbers on the number line, make sure to place a dot DIRECTLY ON the number line at that particular number's location.
Again, check out our textbook for examples!!

Looking at the graph of numbers, we see that the larger number will be to the right of the smaller number.

A number n is between 6 and 12 so 6 < n < 12 or 12 > n > 6

Thursday's Lesson: continuing on ....

Notice the subtle differences in the sentence
Six is greater than a number t
and the phrase
six greater than a number t

Six is greater than a number t becomes 6 > t
while
six greater than a number t becomes t + 6

What about the following inequality:
A number p is greater than a number q
is p > q

The value in cents of d dimes is less than the value in cents of n nickels.

If you need to-- set up your T-charts (refer to your class notes) one for dimes and the other for nickels.

10d represents the number of dimes and 5n represents the number of nickels

so 10d < 5n