THE FIRE SERVICE INSTRUCTOR
The Tenth Installment of a Treatise to Aid Those Responsible for Training Men in the Fire Service to Develop a Systematic Type of Teaching
Chapter IV (Continued)—Helps in Teaching
Changing the Name of a Fraction
Reducing a Fraction: When we change the terms without the numbers. For example, 3 is a common factor of 12, 15 and 39.
1/2 = 2/4 = 4/8 = 8/16 = 16/32
This is called reducing a fraction to higher terms, while the following is called reducing a fraction to lowest terms:
88/96 = 44/48 = 22/24 = 11/12
We see that 11/12 cannot be reduced any lower because we cannot divide the numerator of 11.
Factors: The numbers which multiplied together make another number are called the factors of that number, for examples : 2x2x2x11 = 88.
These were the factors used in reducing 88/96 to 11/12.
Prime Number: A number like 11 which has no factor except itself and one is called a prime number.
Prime Factor: A factor which is a prime number is called a Prime Factor.
Common Factor or Common Divisor: A factor of two or more numbers is called a Common Factor or a Common Divisor of the numbers. For example, 3 is a common factor of 12, 15 and 39.
In making a spring leaf, a blacksmith found that he must use 8/12 of a piece of spring steel. This seemed to him an awkward fraction to use, so he proceeded to reduce it to a simpler fraction.
8/4 / 12/4 = 2/3 Lowest Terms.
By cancelling he could have found the lowest terms in less time.
Reducing to an Improper Fraction
A. has a piece of material 45/8 yards long and 1 yard wide, he wishes to cut this material into strips 1 yard long and 1/8 yard wide. How many strips will he have?
Since 1 = 8/8 we see that 4 = 4×8/2=32/8 Therefore 45/8 = 32/8 + 5/8 = 37/8
37 strips can be cut from the material.
Fire Alarm Systems Study Bulletin—Firemen’s Course
(Note: Part of this Study Bulletin has been omitted.)
The alarm signal system is a very vital part of any fire fighting organization, for even the most highly trained men, the best apparatus and equipment and the most adequate water system all start their light at a great disadvantage unless they get into action very soon after the start of a fire.
It is not sufficient that members of the Fire Department themselves understand the different methods of sending alarms; such information should be common knowledge to all citizens. Members of the department can do much to bring this about.
The prime object of a fire alarm signalling system is to transmit an alarm of fire to the fire fighting force within the shortest possible time after a fire is known to exist, and the best efforts and ingenuity of skilled engineers have been brought to bear on this vital question of saving time in the transmission of alarms.
It is obvious that a fire may be more readily checked in its incipiency than after it has made headway; therefore, no matter how efficient a fire department may be, it will fail in the achievement of its purpose if not supplemented by facilities for obtaining knowledge of the exact location of fires without loss of time.
The fact that human life and property of incalculable value depends upon the rapid and accurate transmission of alarms to the fire department makes the fire alarm system one of the most important of all emergency signalling services.
(To be continued)