A-CALCULATOR.COM 0

## FAQs & How-to's

### How To Use

#### What is A Calculator?

A Calculator is our flagship offering — a free online calculator designed to work like its handheld, electronic counterparts. It can store numbers in memory and calculate percentages. It also includes pi and a square root button.

#### Can I use A Calculator with my iPad, iPhone or Android device?

Sure. Unlike Flash-based alternatives, A Calculator works with iPhone and iPad. In fact, it should work with any Android browser that supports JavaScript.

#### Can I embed this on my website?

Yep! You can use A Calculator for your website as long as you promise to follow our conditions. Here's the embed code:

 <iframe width="315" height="340" src="http://www.a-calculator.com/basic/embed.html" frameborder="0" allowtransparency="true"></iframe> 

#### How do I use the memory buttons?

Here's a list of what the memory buttons do:

• MC — Short for "memory clear". Sets the memory to zero.
• MR — "Memory recall". Retrieves the stored number and displays it onscreen.
• MS — "Memory store". Takes the numeral displayed onscreen and stores it. Anything that used to be in memory is erased by the new number.
• M+ — Adds the onscreen numeral to memory.
• M− — Subtracts the displayed numeral from memory.

To test these buttons, you can enter a number and press MS. It's now stored.

Now you can perform your calculations as usual and even reset the calculator using C. When you're ready to use the stored number, just press MR and it'll be recalled.

#### How do I enter negative numbers?

If you want to perform an operation on negative numbers, you should use the ± button. For instance, if you want to divide −42 by −2, you would simply type 4 2 ± ÷ 2 ± =. If you typed 4 2 ÷ 2 =, you would receive an incorrect answer. More information about this can be found here.

#### How do I use the percent (%) button?

The percent button can be used to find a percentage of another number.

Say you want to add 33 to 26 percent of 33. Then you would type 3 3 + 2 6 %. At this point 8.58 (which is 26 percent of 33) should appear onscreen. To add this to 33, simply press =.

Similarly, to divide 89 by 56 percent of 89, for instance, you would type 8 9 ÷ 5 6 % =.

#### If I enter 2×−3= I get −1. Shouldn't I get −6?

Just as you would expect from most electronic calculators, only the most recently pressed operator button, , is used. For example, if you typed in 2 × ÷ ÷ + 3 = the result would be the same as if you entered 2 + 3 =.

If you want to perform an operation on negative operands, you should use the ± button which negates the displayed numeral. For example, to find 2 times −3, you would enter 2 × 3 ± =.

#### What is an expression?

An expression in math is like a sentence in English.

An expression is just a combination of symbols that have a meaning or value. It can contain numerals, operators and other symbols. For example, 2+2.5 and 2÷9+√4 are both mathematical expressions.

#### What is an operand?

An operand is a symbol which is affected by an operator. Two, nine and four in the expression 2+√9÷4 are all operands.

#### What is an operator?

An operator is a symbol which effects one or more operands. In the expression, 2+2.5, the addition operator (+) operates on 2 and 2.5 to produce 4.5.

#### I receive a long answer. How do I round it to the nearest whole or decimal place?

The purpose of rounding is to make a number easier to work with. The problem is that by rounding you lose some accuracy. To make sure you lose as little accuracy as possible, you should choose the number which is closest to the original (unrounded) one. Take the number 7.1 as an example. To round it to the nearest whole, you'd simply choose 7 because 7 is closer to 7.1 than 8 is.

Rounding a 23.5 is tricky, because it's just as close to 23 as it is to 24. There are a few different methods for dealing with this case, though the most commonly used is to round up. In this case, 23.5 rounds up to 24.