Using a Scientific Calculator
by Ron Kurtus (revised 8 July 2013)
A scientific calculator is an advanced version of the ordinary hand-held calculator or computer application that you may often use. It usually includes trigonometric functions such as sine and cosine, exponential functions such as square root, and miscellaneous mathematical functions. Some expensive scientific calculators even include graphic and problem-solving capabilities.
We have some simple scientific calculations in the School for Champions lessons and have included an online calculator to use. You can access it from the lessons with calculation examples. This lesson includes instructions to use such a calculator.
Questions you may have include:
- What is needed to use the calculator?
- What does the calculator look like?
- How do you use it?
This lesson will answer those questions. Useful tool: Units Conversion
The online calculator is used just like a real one. But note that you need can't use your keyboard to input numbers. You need to click on the numbers and functions on the calculator.
How to use it
We assume you know how to use a simple calculator to add, subtract, multiply and divide, so we'll just explain the more complex functions.
- sin, cos, tan, inv
- x^2, x^y and sqrt
- pi, ln, and n!
If you enter a number by mistake, you can use C to clear that number. It does not clear previous calculations.
If you want to clear what is on the display, click AC ("all clear"). Note that AC does not clear the memory.
Clear mistake exercise
- Click AC to clear everything you may have done before.
- Enter 12 + 3 but then realize that you really meant to enter 13 instead of 3.
- Now click C to clear the 3. Then enter 13 and click = to get the correct answer of 25.
Note that different calculators have different expressions to clear the entries. Many calculators use C to clear an entry and AC to clear all, as does our calculator. On the other hand, the calculator provided with Microsoft Windows uses CE to clear entry and C to clear all. You need to be aware of which nomenclature your calculator uses.
For some calculations, you may want to remember one calculation to use later. You can add a calculation into memory by clicking the M+ button. Then you recall it later with the MR button. You clear the memory with the MC button.
Note that M+ will add whatever you have on the display to whatever is already in the memory, so it is good to click MC before adding with M+, unless you have recently started the calculator.
Adding to memory exercise
You want to add 1 + 2 and then multiply that by the sum of 8 - 3.
You should get a total of 15.
To see how to add more to memory, click M+ and then MR. The 15 should be added to the 3 already in memory, giving you 18 when you recall memory.
1/x is simply 1 divided by whatever x is.
- Enter 5 and click 1/x to get 1/5 = 0.2
sin, cos, tan, inv
Functions used in trigonometry concerning angles are sine (sin), cosine (cos), and tangent (tan).
- If you would want to find the sine of an angle of 30 degrees, you would enter 30 and then the sin button. The answer should be 0.5.
There is also the capability of going backwards. If you know the sine, cosine or tangent, you can find the angle in degrees for that function. This is called the inverse (inv) operation. Those values are also called the arcsine, arccosine and arctangent.
- Enter 0.5, click inv and then click sin. You should get 30 (degrees) for an answer.
x^2 and x^y
x^2 means "x squared" or x2. That also means x times x or x*x.
x^y means x raised to the y power. For example, if y = 3, you would have x cubed or x3. Using this operation is tricky.
Suppose you wanted to calculate 34. That is 3*3*3*3 or 3 times itself 4 times.
sqrt means the square root of the number. It is often seen as the symbol √, but that may not show up in some older browsers.
The square root of a number is the value multiplied by itself that equals the original number.
Find the square root of 121:
- Enter 121 and click sqrt. You should get an answer of 11. (11*11 = 121.)
(You can also calculate the square root with x^y, using y = 0.5.)
pi is the number 3.14159... used in many geometry calculations. It is more often seen as the Greek letter π, but that may not show up in some older browsers.
ln is called the natural logarithm of a number. This operation is not used much.
n! represents n factorial. That means if n = 7, n! = 7*6*5*4*3*2*1. This operation is not used much.
You can use the online scientific calculator to help solve various problems. It is very similar to actual battery powered calculators.
Use good tools
Resources and references
eCalc Scientific Calculator (downloadable) - Includes instructions and many features
Scientific Calculator - Online version from Math.com
Some calculators available from Amazon.com.
Hewlett Packard 49G+ Graphing Calculator - Costs about $120
HP 33S Scientific Calculator (F2216A) - Costs about $48
Texas Instruments BA35 Calculator - Costs about $21
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Using a Scientific Calculator