Basic Mathematics for College Students

6 Chapter 1 Whole Numbers

Inequality Symbols

means is less than

means is greater than

Success Tip To tell the difference between these two inequality symbols,

remember that they always point to the smaller of the two numbers involved.

85 58

Points to the

smaller number

 

EXAMPLE (^5) Place an or an symbol in the box to make a true
statement: a.3 7 b.18 16
StrategyTo pick the correct inequality symbol to place between a pair of
numbers, we need to determine the position of each number on the number line.
WHY For any two numbers on a number line, the number to the leftis the smaller
number and the number to the rightis the larger number.
Solution
a.Since 3 is to the left of 7 on the number line, we have 3 7.
b.Since 18 is to the right of 16 on the number line, we have 1816.



 

Self Check 5

Place an or an symbol in
the box to make a true
statement:

a. 12 4

b.7 10

Now TryProblems 59 and 61

 

5 Round whole numbers.

When we don’t need exact results, we often round numbers. For example, when a

teacher with 36 students orders 40 textbooks, he has rounded the actual number to the

nearest ten,because 36 is closer to 40 than it is to 30. We say 36, rounded to the nearest

10, is 40. This process is called rounding up.

Round up 36 is closer to

40 than to 30.

30 31 32 33 34 35 36 37 38 39 40

When a geologist says that the height of Alaska’s Mount McKinley is “about

20,300 feet,” she has rounded to the nearest hundred,because its actual height of

20,320 feet is closer to 20,300 than it is to 20,400. We say that 20,320, rounded to the

nearest hundred, is 20,300. This process is called rounding down.

Round down

20,320 is closer to

20,300 than 20,400.

20,300 20,310 20,320 20,330 20,340 20,350 20,360 20,370 20,380 20,390 20,400