# Using Calculators Worksheets

How to Use a Calculator - When we calculate two plus two, we imagine a number line, start at two and hop over a couple of spots to get to four (or at least we did until we memorized the answer). Simple - so simple, in fact, that "putting two and two together" is an analogy for deducing something obvious. But what if you cannot imagine a number line? What if you are a little, gray, button-covered box full of electrons? How, then, do you calculate that two plus two equals four? The process itself is not so simple, but once you understand how this basic arithmetic operation works in a calculator, you can "put two and two together" as to how it performs much more complicated calculations. First off, the input: when you press the "2" key, the button compresses a rubber pad below it, which in turn pushes an electrical wire into contact with another one, creating a circuit between them. Powered by a battery, electricity flows along the circuit to transistors.

• ### Basic Lesson

Demonstrates doing basic operations can be fun, if you turn the calculator upside down. What word does the following difference make when we turn the calculator upside down?

• ### Intermediate Lesson

Shows students how to use a calculator to break codes using a word key. Work out the sums, find the letter, crack the code!

• ### Independent Practice 1

Contains 20 mixed operations. The solutions all spell out words when you turn your calculator upside down. Write the number and upside-down word that these operations make.

• ### Independent Practice 2

Features a word key and 20 calculator operations that spell out words.

• ### Homework Worksheet

Features 6 operations that spell out words and 6 operations that when used with a key, spell out words.

• ### Skill Quiz

10 Calculator Fun questions. Scoring matrix is provided.

• ### Lesson and Practice Answer Key

Answers for the lesson and practice sheets.

• ### Homework and Quiz Answer Key

Answers for the homework and quiz.

#### Here are a couple calculator riddles to tickle your friends' funny bones:

What do you get when you cross a calculator and a friend? A friend you can count on! What is the easiest way to count a herd of cattle? Use a cow-culator! Learn more about this magic invention with our article: The History of Calculators