Report

Map Scale MAP SCALE… • A SCALE shows the relationship between the distance on a map and the ACTUAL distance on the EARTH’s SURFACE • Scale can be represented in 3 ways: 1) direct statement/verbal 2) Line scale 3) Representative Fraction Scale (RF) DIRECT STATEMENT… • Uses words to describe the relationship between a distance on a map and a specific distance on the Earth’s surface FOR EXAMPLE: 1 cm to 10 km OR 1 cm = 10 km What does this direct statement mean? For example… • If you have measured the distance between Hamilton and Toronto and found it to be 25 cm on the map, and the direct statement reads 1 cm = 2 km, how far would it be in km? HOW DO WE FIGURE THIS OUT? Solution… 1 cm 25 cm = 2 km X 1 x X = 2 x 25 X = 50 Therefore, the actual distance between Hamilton and Toronto is 50 km 5 STEP PROCESS 1) Write down the statement: 1 cm = 2 km 2) Add in the information you know: 1 cm = 2 km 25 cm X 3) Eliminate (the same) units: 1 cm = 2 km 25 cm X 4) Cross Multiply: 1 x X = 25 x 2 5) Therefore statement… LINE (Linear) SCALE… • A special kind of ruler on the map that is divided into equal units of distance • Always includes the units of measurement on the Earth’s surface SO, HOW DOES THIS WORK? REPRESENTATIVE FRACTION SCALE (R.F)… • The scale is written as a ratio FOR EXAMPLE: 1:50 000 • This means: ONE unit on the map represents 50 000 of the same units on the Earth’s surface 1:50 000 The FIRST term of the ratio: The SECOND term of the ratio: – is always 1 – Represents the distance on the map in units – Represents the distance on the Earth – Same unit of measurement as the first term SCALE CONVERSION 1 km = 1 000 m 1 m = 100 cm 1 km = 100 000 cm CONVERTING RF TO DIRECT STATEMENTS From RF scale direct scale: divide the right side of the equation by 100 000, to change centimetres to kilometres convert 1:50 000 RF to direct statement 1:50 000 1 cm = 50 000 cm 1 cm = 50 000 km 100 000 1 cm = 0.5 km or 1 cm = 500 m CONVERTING DIRECT STATEMENTS TO RF From direct statement scale RF scale: multiply the right side of the equation by 100 000 to change kilometres into centimetres convert 1 cm = 2.5 km into a RF 1 cm = 2.5 km 1 cm = (2.5 x 100 000) cm 1 cm = 250 000 cm or 1:250 000 IN SUMMARY… Converting R.F to Direct Statements: divide right side by 100 000 to change cm km Converting Direct Statements to R.F: Multiply right side by 100 000 to change km cm QUESTION: What does 1 cm = 0.5 km mean? Answer: 1cm on the map represents 0.5 km on the earth’s surface QUESTION: Direct Statement: 1 cm = 35 km If the map distance between points A and B is 9 cm, what is the real distance? Answer: 9cm = 315km QUESTION: Direct Statement: 1 cm to 250 km If two places are 17 cm apart on the map, what is the actual distance between them? Answer: 17cm = 4250km QUESTION: In your own words, what does 1:250 000 mean? Answer: One centimeter on ant map represents 250 000 cm on the earth’s surface What does 1:3 000 000 mean? QUESTION: Convert the RF into a DIRECT STATEMENT 1:250 000 Answer: 1cm = 2.5km OR 1cm to 2.5km QUESTION: Convert the RF into a DIRECT STATEMENT 1:63 000 000 Answer: 1cm = 630km or 1cm TO 630km QUESTION: Convert the direct statements to RF scales 1 cm to 5 km Answer: 1cm = 500 000cm QUESTION: Convert the direct statements to RF scales 1 cm to 25 km Answer: 1:2 500 000 QUESTION: The line scale on a map indicates that 4 cm represents 20 km. What is the RF? Answer: 1:500 000 QUESTION: The line scale on a map indicates that 1.5 cm represents 50 km. What is the RF? Answer: 1:3 333 333