SI Measurement System Presentation Name Course Name Unit # – Lesson #.# – Lesson Name SI Measurement System Introduction to Engineering Design © 2012 Project Lead The Way, Inc.

The International System of Units (SI) Presentation Name Course Name Unit # – Lesson #.# – Lesson Name The International System of Units (SI) The International System of Units (SI) is a system of units of measurement consisting of seven base units The abbreviation SI is from the French “Systeme Internationale d’unites” SI is the most widely used system of measurement in the world The United States is the only industrialized nation that has not adopted the SI system

The International System of Units (SI) Presentation Name Course Name Unit # – Lesson #.# – Lesson Name The International System of Units (SI) The modern SI system evolved from the older metric system. Metric system only had three base units centimeters, grams, and seconds. While the SI system has evolved to seven base units listed below The base unit is the fundamental unit (basic unit, essential unit) in a system of measurement *The kilogram not gram is the base unit Base Unit Name Symbol Measurement meter m length kilogram* kg mass second s time ampere A electric current kelvin K Temperature candela cd luminous intensity (brightness) mole mol quantity, the amount of something (usually the amount of a substance) 6.02x1023 of something

The International System of Units Presentation Name Course Name Unit # – Lesson #.# – Lesson Name The International System of Units Often referred to as the metric scale (cause SI came from metric) Prefixes indicate an integer power of 10 Power of 10 Prefix Abbreviation 101 deca- da 102 hecto- h 103 kilo- k 106 Mega- M 109 Giga- G 1012 Tera- T Power of 10 Prefix Abbreviation 10-1 deci- d 10-2 centi- c 10-3 milli- m 10-6 micro- µ 10-9 nano- n 10-12 pico- p

Presentation Name Course Name Unit # – Lesson #.# – Lesson Name

Recording Measurements Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Recording Measurements A measurement always includes a value A measurement always includes unit of measurement A measurement always involves uncertainty A measurement is the best estimate of a quantity Bob weighs 142 lbs. That is no exact. No one can weigh exactly 142 lbs. Value Unit

Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Metric Scale A typical metric scale ruler often includes a 30+ centimeter scale Each centimeter is divided into 10 millimeters

The Millimeter The millimeter is the smallest increment found on a typical metric scale 1 mm which is 0.1 cm

The Millimeter The next larger marking on a metric scale shows 5 millimeters 5 mm which is 0.5 cm

The Millimeter Largest markings on a metric scale represent centimeters (cm) These are the only marks that are actually numbered 1 cm = 10 mm

Measurement: Using a Decimal Scale Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Measurement: Using a Decimal Scale How long is the rectangle? Let’s look a little closer

Measurement: Using a Decimal Scale Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Measurement: Using a Decimal Scale How long is the rectangle?

Recording a Measurement Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Recording a Measurement How long is the rectangle? Remember the general rule Decimal Scaled Instruments – Record all digits that you can certainly determine from the scale markings and estimate one more digit Best Estimate = 3.84 cm or 38.4 mm

Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Your Turn How would you record the length of this rectangle? 6.32 cm or 63.2 mm

Find the width of the blue and red rectangle Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Find the width of the blue and red rectangle BLUE RED

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