Most engineering task include calculations and measurements. So it it is important to understand the basics.

- abacus third millennium b.c. – One of the first devices to augment human intelligence. Also called a counting frame, a calculating tool for performing arithmetic processes. The abacus was in use centuries before the adoption of the written modern numeral system and is still widely used by merchants and clerks in China, Japan, Africa, India and elsewhere.

- electronic calculator – a small, portable electronic device used to perform both basic and complex operations of arithmetic. The first solid state electronic calculator was created in the 1960s, building on the extensive history of tools such as the abacus, developed around 2000 BC; and the mechanical calculator, developed in the 17th century. It was developed in parallel with the analog computers of the day.

Measurement

- units – U.S., metric
- scale – atomic, microscopic, visible, planetary, astronomical
- tracking – movement, change, time
- tools – ruler, seismometer

Calculation

- scientific
- statistics
- calculus, differential equations

Calculators

- scientific
- graphing
- visualization
- unit conversion

Mobile measuring and calculating – there is an app for that…

- measuring – ruler, seismometer
- calculator – scientific, graphing
- recording – camera, notebook, voice recorder, data storage
- tracking – location, compass, GPS
- reference – topographical maps, biological molecule structures, periodic table, science glossary, unit conversion

**What’s the problem?**

Doing lots of complex arithmetic calculations quickly and accurately is required for many jobs and applications. Making change at the grocery story. Building bridges. Designing satellite telescopes.

**Ask**– How could a small hand-held electronic device be created to perform mathematical calculations? How would the user input information? How would the results be displayed?**Imagine**– There are many other electronic device components used for other applications? How can these be adapted or modified for use in a calculator? What special functions would be needed to make this device?**Design, Build**– Using ideas from other devices, how would the components be assembled? How could a unit be manufactured to keep costs low?**Improve**– Over time the electronic calculators have been made smaller and smaller as the technology improved. The cost has been reduced as millions of the devices are sold every year.

**That’s engineering**

- liquid crystal display (LCD) – a special thin flat panel that can let light go through it, or can block the light. The panel is made up of several blocks. Each block is filled with liquid crystals that can be made clear or solid, by changing the electric current to that block.

**Engineering ideas**

- electronics, computation, solid state, analog, digital, LED display, math function, integrated circuit, keypad, liquid crystal display, microprocessor

**Do it**

Here are some challenges for you to work on…

- Calculator Riddles – try these. Did you get an answer that makes sense? Did you have to turn the calculator upside dowd to see the “answer”?

**Learn more…**

- 25 iPad Apps Every Engineer Needs – great list of smartphone apps
- History of Electronic Calculators