## Practice Exercises on Addition of Integers

In the previous post, we have learned about adding positive and negative integers particularly on how to add integers with different signs. In this post, I am going to give you 10 exercises on adding integers. I will give the answers below for you to be able to check if your answers are correct. Also, I am going to omit the + sign before the positive integers because this is not usually shown in the exam. This means that 3 will automatically mean +3 unless a – sign precedes it.

1. 28 + 12
2. 14 + 11
3. 24 + 15
4. 16 + 31
5. 23 + 46 + 15
6. 45 + 12 + 16
7.  12 + 15 + 62
8. 22 +  36 + 36
9. 12 + 18 + 12 + 18
10. 31 + 55 + 41 + 32 + 10

## How to Add Positive and Negative Integers

One of the topics in basic mathematics  that will likely be included in the the Philippine Civil Service Exam both professional and subprofessional are operations on integers. Although a few Civil Service test items may be given from this topic,  it is important that you master it because a lot of calculation in other topics will need knowledge of integers and its operations (addition, subtraction, multiplication, division). For example, solving some word problems in mathematics and solving equations will need knowledge on operations of integers.

Integers are whole numbers that are either positive or negative. Examples of integers are -5, 6, 0, and 10. If we place this on the number line, negative integers are the integers that are below 0 (left of 0), while the positive integers are the integers above 0 (right of 0).

##### Adding Integers that Are Both Positive

When you add integers that are both positive, it is just like adding whole numbers. Below are the examples.

Example 1: +2 + +4 = +6

Example 2: +9 + +41 + +6 + = +56

Example 3: +120 + +13 + +12 + = +145

Although we have created a small + before the number to indicate that it is positive, in reality, only negative numbers have signs. This means that +2 + +4 = +6 is just written as 2 + 4 = 6.

##### Adding Integers that Are Both Negative

Adding number that are both negative is just the same as adding numbers that are both positive. The only difference is that if you add two negative numbers, the result is negative.

Example 1: 5 + 8 = 13

Example 2: 10 + 18 + 32 + = 60

Example 3: 220 + 11 + 16 + = 247

##### How to Add Positive and Negative Integers

Before adding, you should always remember that +1 and 1 cancel out each other, or +1 + 1 is 0. So the strategy is to pair the positive and negative numbers and take out what’s left.

Example 1:  What is +13 + 8?

Solution:

We pair 8 positives and 8 negatives to cancel out. Then what’s left is of +13 is +5. In equation form, we have

+138 = ++ +8 + 8+5 + (+88) = +5 + (0) = +5

Example 2: What is +17 + 20?

Solution:

We pair 17 negatives and 17 positives. What’s left of 20 is 3. In equation form, we have

+1720 = +17 + (173) =  (+17 + 17) + 3 = 0 + 33

Example 3: What is +16 + +37 + 20 + 3 +9 ?

That is +16 + +37 = +53 and  20 + 3 +9 = 32.

So, the final equation is +53  + 32. We pair 32 positives and 32 negatives leaving 21 positives.

In equation form, we have

+53  + 32 = +21  +3232+21  + (+3232) = +21 + 0 = +21

By now, you will have realized, that adding integers is pretty easy. If you have questions, please fill out the comment box below.

## What is the Philippine Civil Service Examination?

The Philippine Civil Service Examination is given by the Civil Service Commission (CSC) to aspirants who want to work in the Philippine government. All government employees aside from a few exceptions (like passing selected board exams) are required to take the CSC Examination to be granted tenure.

There are two levels of Civil Service Examinations: Subprofessional and Professional. The Subprofessional level is for those who have finished 2-year courses or below. Those who have graduated 4-year courses or beyond are advised to take the Professional level.

The CSC examination is mainly composed of English and Mathematics proficiency. The other areas include Filipino, office filing and ethics, and Philippine constitution particularly Republic Act 6713.  As of this writing, the passing score of the CSC Examination is 80%.

This blog will serve as a Civil Service Reviewer for those who want to take the examination. I will be discussing questions that are similar to the examination and provide answers, detailed explanations, and tips. I will also give online mock exercises and examinations. In addition, I will also provide updates, links, and examination results.

For now, I will be discussing Mathematics and English subjects. The other subjects such as Philippine constitution will be discussed later by more qualified persons.

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