Skip to main content

1.2 Addition

ADDITION: ADDING TO A SUM OR TOTAL

Addition is used when combining items, or putting items together to obtain a total. It helps answer questions such as "How many?" "How much?" or "How far?" Let's look at different ways that addition can be used. Some words used often to refer to addition are "plus", "and", "the sum of", "total", or "added to".

Example 1 - Pedro's crew has 4 pulaskis. Jane's crew has 6 pulaskis. How many pulaskis do they have together?

Addition Chart

As shown the the figure above, the addition needed to answer this question is: 4 + 6 = 10.
 

ADDITION IS USED IN COMBINING DISTANCES OR LENGTHS.

Example 2 - Crew 1 constructs 14 chains of handline on the day shift. Crew 2 constructs 11 chains of handline on the night shift. How many chains did crew 1 and 2 construct altogether?

14 chains + 11 chains = 25 chains

 

ADDITION IS USED TO FIND THE DISTANCE AROUND AN OBJECT.

The total distance around an object is called the perimeter.

Example 3 - The Division Supervisor (DIVS) used two dozers to construct a line. The dozers cleared a line of the following shape. How many chains of dozer line were constructed?
 

Addition Chart

45 chains + 36 chains + 28 chains + 29 chains + 110 chains = 248 chains

 

ADDITION IS USED IN COMBINING AREAS.

Example 4 - The day shift had two spot fires that were contained at 6 acres and 8 acres each. What was the total area of the spot fires that burned during the day shift?

6 acres + 8 acres = 14 acres

 

ADDITION IS USED IN COMBINING VOLUMES.

Example 5 - Herman pumped 30 gallons of fuel into one tank, 25 gallons into the next tank, and 27 gallons into the last tank. How many gallons of fuel did Herman pump?

30 gallons + 25 gallons + 27 gallons = 82 gallons

 

ADDITION IS USED IN COMBINING LARGER NUMBERS.

When adding several numbers, especially large numbers, add the ones (1s) first, then the tens (10s), then the hundreds (100s), and so on.

Example 6 - Add: 548 + 365
First, add the ones. There are 13 ones, or 1 ten and 3 ones. Write 3 in the ones column and "carry over" the 1 above the tens.
Next, add the tens. There are 11 tens, or 1 hundred and 1 ten. Write 1 in the tens column and the 1 above the hundreds.
Now, add the hundreds. There are 9 hundreds.addition of large numbers
The answer to 548 + 365 is 913.

ADDING POSITIVE AND NEGATIVE NUMBERS

Numbers can be positive or negative. Positive numbers are indicated with a + sign, or have no sign. If a number is written without a sign, the sign is assumed to be positive. Negative numbers are indicated with a - sign. For example, a negative pressure may be indicated as -25 inches of Hg, or as a vacuum of 25 inches of Hg. 

Signs are important in adding numbers. Here are some easy rules to help determine the sign of a sum: 
image tag sign rules for addition

Example 7 - Adding numbers with like signs.
5 + 5 = 10
3 + 3 = 6
-5 + (-5) = -10
-3 + (-3) = -6
 

Example 8 - Adding numbers with unlike signs. Notice that the sign of the larger number is the sign that the answer will have.
5 + (-3) = 2
3 + (-3) = 0
3 + (-5) = -2
2 + (-3) = -1

NWCG Latest Announcements

Updated NWCG Standards for Airtanker Base Operations, PMS 508

Date: March 31, 2025
Questions?  Please contact:
Airtanker Base Operations Unit

The updated NWCG Standards for Airtanker Base Operations (SABO), PMS 508 standardizes operations and procedures at interagency airtanker bases to ensure safe, efficient, and effective operations in support of interagency goals and objectives.

References:

NWCG Standards for Airtanker Base Operations, PMS 508

WFSTAR 2025 Core Component Module Package and 2024 Fire Year in Review Now Available

Date: March 14, 2025
Questions?  Please contact:
Joe Schindel at mschindel@blm.gov
 

The 2025 Core Component Module Package for RT-130, Wildland Fire Safety Training Annual Refresher (WFSTAR) and the 2024 Fire Year in Review are now available on the NWCG website. The 2025 Core Component Module Package provides all content needed to deliver RT-130.

References:

2025 Core Component Module Package

2024 Fire Year in Review Module

NEW! NWCG Wildland Urban Interface Mitigation Field Guide, PMS 053

Date: March 12, 2025
Contact: Wildland Urban Interface Mitigation Committee

The NWCG Wildland Urban Interface Mitigation Field Guide, PMS 053 provides mitigation practitioners at all experience levels with recommendations on the most effective and efficient ways to accomplish mitigation work in communities at risk to wildfire damage or destruction. The content in this guide was written in coordination with the NWCG Standards for Mitigation in the Wildland Urban Interface, PMS 052.

References:

NWCG Wildland Urban Interface Mitigation Field Guide, PMS 053 

Updated, NWCG Standards for Wildland Fire Module Operations, PMS 430

Date: March 11, 2025
Contact: Fire Use Subcommittee
Wildland Fire Module Unit

The NWCG Standards for Wildland Fire Module Operations, PMS 430 standardizes procedures and expectations for Wildland Fire Modules (WFMs). These standards are to be used by staff, supervisors, specialists, and technicians for planning, administering, and conducting WFM operations. These standards will also be used as a measure of WFM qualifications, capabilities, and expected performance, for both Type 1 and Type 2 WFMs.

References:

NWCG Standards for Wildland Fire Module Operations, PMS 430