Understanding and Using the METRIC SYSTEM SI Standard

Understanding and Using the METRIC SYSTEM [SI, Standard International] Système international d’Unités 1

“I CAN” statements ‗ name the 7 base units This means that I can identify the correct physical quantity being represented solely by its unit and/or its corresponding symbol. ‗ name the most commonly used prefixes This means that I can list - in the correct order of magnitude - at least 6, preferably 10, words that precede any of the base units. ‗ perform metric conversions This means that I can express a given measurement into any of the metric prefixes. Ppt 2010_ES 02 Metric System

7 base units Physical Quantity Name of Unit Symbol Length meter m Mass gram g Time second s Temperature kelvin K Electric current Ampere D Amount of substance mol Luminous intensity candela cd Volume liquid is not a fundamental unit, but it is a direct measurement 3

Main GOALS and ADVANTAGES are: i. A single base unit for any physical quantity ii. No need for conversion factors iii. All multiples and subdivisions are decimal factors or of powers of ten [prefixes] 4

PREFIXES A WORD that precedes the base unit to identify the magnitude / the size of the measurement. i. e. its function is to multiply or divide the measure by a factor of ten, one hundred, or a positive integer power of one thousand Those prefixes are common to all types of measurements. 5

PREFIXES [to know] King Henri k i l o h e c t o k h Dr. Ank d a Bad Disgusting Chocolate b a s e d e c i ABBREVIATION da -- d Milk c e n t i m i l l i c m 6

PREFIXES [to know] King Henri DAnced Bad Disco Country Music k i l o h e c t o k h c e n t i m i l l i ABBREVIATION da -- d c m d a b a s e d e c i 7

PREFIXES [to know] King Henri Dr. Ank Bad D k i l o h e c t o k h d a b a s e isgusting Chocolate Milk c e n t i m i l l i c m d e c i ABBREVIATION da -- d 8

Prefix Symbol Magnitude Meaning (multiply by) Tera- T 1012 1 000 000 Giga- G 109 1 000 000 Mega- M 106 1 000 kilohectodeca- k h da 103 102 10 100 10 BASE UNIT - - - decicentimillimicro- d c m u (mu) 10 -1 10 -2 10 -3 10 -6 0. 1 0. 001 0. 000 001 nano- n 10 -9 0. 000 001 pico- p 10 -12 0. 000 000 001 9

Prefix Symbol Magnitude Yotta- Y 1024 Zetta- Z 1021 Exa. Petafemtoatto- E P f a 1018 1015 10 -18 zepto- z 10 -21 yocto- y 10 -24 Meaning (multiply by): 1 000 000 000 000 1 000 000 000 001 0. 000 000 000 000 001 10

The simplicity of the system is derived from using the arithmetic base 10. One simply needs to shift the decimal point or change an exponent to express results with a different prefix. 11

SAMPLE PROBLEM: AN ANSWER TO A CALCULATION GAVE A VALUE OF “ 54, 500 meters” ALTHOUGH ‘CORRECT’, THE VALUE IS LARGE AND CUMBERSOME; IT CAN BE SHORTENED AND REDUCED TO A SMALLER EXPRESSION BY A SIMPLE CONVERSION… 12

kilometer Kilo Hecto Deca BASE UNIT Deci REMEMBER… To change to a larger prefix, move the decimal to the LEFT 54, 500 meters Centi Milli = 54. 5 kilometers 13

kilometer kilo meter hecto deca BASE deci centi milli 54, 000 meters = 54 km 14

SAMPLE PROBLEM: A student has this value for the mass of a certain object: 1. 43 gram However, the formula in which she has to use the value calls for the mass in milligrams… A quick conversion by moving the decimal point is easy: 15

REMEMBER… 1. 43 Kigram lo To change to a smaller prefix, move the decimal to the RIGHT [fill in zero’s] Hecto Deca gram BASE UNIT Deci Centi milligram Milli 16

REMEMBER… 14. 3 decigram Kilo To change to a smaller prefix, move the decimal to the RIGHT [fill in zero’s] Hecto Deca gram BASE UNIT Deci Centi milligram Milli 17

143. centigram Kilo Hecto gram = 1, 430 REMEMBER… milligrams To change to a smaller prefix, Deca move the decimal BASE to the RIGHT UNIT [fill in zero’s] Deci Centi milligram Milli 18

gram kilo hecto deca BASE milligram deci centi milli 1. 43 gram = 1, 430 mg 19

To change to a Kilo smaller prefix, move the decimal to the Hecto RIGHT Deca [fill in the zero’s, if BASE necessary] UNIT Deci To change to a larger prefix, move the decimal to the LEFT Centi Milli [fill in the zero’s, if necessary] 20

Convert the following measurement as indicated: 95 cm to meters A. 0. 95 hm B. 9. 5 m C. 950 m D. 0. 95 m 21

Convert the following measurement as indicated: 1. 1 L to milliliters A. 0. 11 m. L B. 11 m. L C. 110 m. L D. 1, 100 m. L 22

Convert the following measurement as indicated: 17, 000 m to kilometers A. 1, 700 km B. 17 km C. 170 km D. 170, 000 km 23

Convert the following measurement as indicated: 500 kg to grams A. 5 g B. 50 g C. 500, 000 g D. 0. 5 g 24

Which SI prefix means one-hundredth (1/100)? A. Nano. B. Micro. C. Milli. D. Centi- 25

1) 170. 4 m =_______ cm 2) 564 dag =_______ g 3) 58 dg =_______ mg 4) 600 L =_______ k. L 5) 0. 0923 km =_______ mm 6) 49 hg =_______ g 7) 210 c. L =_______ d. L 8) 45700 cg =_______ kg 9) 82. 4 nm =_______ m 1)10) 4. 51 x 103 L =_______ m. L 26

ANSWERS 1. 17040 cm 2. 5640 g 3. 5800 mg 4. 0. 600 k. L 5. 92300 mm 6. 4900 g 7. 21. 0 d. L 8. 0. 457 kg 9. 0. 0824 m 10. 4. 51 m. L; write out 4. 51 x 103 L = 4510 L, the decimal is understood to be after the zero. Now count UP from the prefix to the m (milli) prefix. You counted three places, so move the decimal to the LEFT three places = 4. 51 m. L 27

1. 40 ml = _______ L 2. 5000 L = _______ kl 3. 8 g = _______ kg 4. 12000 L = _______ kl 5. 50 mg = _______ g 6. 6000 m = _______ km 7. 200 kg = _______ g 8. 10000 g = _______ kg 9. 500 ml = _______ L 10. 1 L = _______ ml 11. 4000 L = _______ kl 12. 400 cm = _______ m 13. 20 ml = _______ kl 14. 7000 ml = _______ L 15. 7 cm = _______ mm 16. 9000 L = _______ ml 17. 6 m = _______ mm 18. 1000 cm = _______ m 19. 11 km = _______ m 20. 80 mg = _______ kg 21. 3 m = _______ mm 28

Directions: Find the greatest metric measurement in each problem. 1. 500 cm; 5000 mm; 4 m 2. 0. 2 L; 240 m. L; 50 c. L 3. 3000 mg; 250 cg; 3 kg 4. 4 L; 5000 m. L; 23, 000 c. L 5. 17 m; 17, 040, 000 cm; 17, 400, 005 mm 6. 2000 cg; 25, 300 mg; 2. 5 Kg 7. 3400 cg; 4. 5 kg; 7, 000, 843 mg 8. 23 L; 4. 3 k. L; 6, 000, 320 m. L 9. 820, 000 cg; 38 kg; 600, 002, 394 mg 10. 34, 948, 304 m. L; 32, 394 c. L; 55 k. L 11. 2 km; 5550 m; 64, 430 cm 12. 435, 678 g; 4. 32 kg; 321, 900, 484 mg 13. 74, 000 cm; 824, 000 mm; 2 km 14. 84, 000 m. L; 3. 4 k. L; 750 L 15. 23, 436 g; 268, 980 mg; 2. 3 kg 29

MORE PROBLEMS http: //virtual. yosemite. cc. ca. us/smurov/ex 1 -1. htm http: //www. fordhamprep. org/gcurran/sho/index. htm 30