Basic Mathematics for College Students

16 Chapter 1 Whole Numbers

Self Check 2

Add:

Now TryProblems 29 and 33

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Self Check 1

Add:

Now TryProblems 21 and 27

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We can write this addition problem in horizontal or vertical formusing an

addition symbol ,which is read as “plus.” The numbers that are being added are

called addends and the answer is called the sumor total.

Horizontal form Vertical form

To add whole numbers that are less than 10, we rely on our understanding of basic

addition facts. For example,

2 + 3 = 5, 6 + 4 = 10, and 9 + 7 = 16

If you need to review the basic addition facts, they can be found in Appendix 1, at

the back of the book.

To add whole numbers that are greater than 10, we can use vertical form by

stacking them with their corresponding place values lined up. Then we simply add the

digits in each corresponding column.

Addend

Addend

 Sum



4 

 5

9

We read each form as

"4 plus 5 equals (or is) 9."

(^4)   (^5)   (^9) 
Addend Addend Sum



EXAMPLE (^1) Add:
Strategy We will write the addition in vertical form with the ones digits in a
column, the tens digits in a column, and the hundreds digits in a column. Then we
will add the digits, column by column, working from right to left.
WHY Like money, where pennies are only added to pennies, dimes are only added
to dimes, and dollars are only added to dollars, we can only add digits with the same
place value: ones to ones, tens to tens, hundreds to hundreds.
Solution
We start at the right and add the ones digits, then the tens digits, and finally the
hundreds digits and write each sum below the horizontal bar.
Hundreds column
Tens column
Ones column
Vertical form
The answer (sum)
Sum of the ones digits: Think: 1  3  5 9.
Sum of the tens digits: Think: 2  2  4 8.
Sum of the hundreds digits: Think: 4  1  2 7.
The sum is 789.
  


4 2 1

1 2 3

 2 4 5

7 8 9

  

421  123  245

If an addition of the digits in any place value column produces a sum that is

greater than 9, we must carry.

EXAMPLE (^2) Add:
Strategy We will write the addition in vertical form and add the digits, column by
column, working from right to left. We must watch for sums in any place-value
column that are greater than 9.
WHY If the sum of the digits in any column is more than 9, we must carry.

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