Calculator Lite a simple online calculator designed to work like it is hand-held
Support Development
PayPal ● 
Bitcoin Address: 1sM2BrTH8BRgt3quiASK8TmYSafutNvDo
Ether Address: 0xCf9eaAc56992e12EB61fD46342172d4EEff5C8e4

"Calculator Lite" is a simple online calculator designed to work like it is hand-held.


  1. What is new in this version?

    Check this link for information about your recent update.

  2. How to add/remove the toolbar button in Firefox?

    To add/remove the toolbar icon right-click on a free space in your Firefox toolbar and select "Customize...". Now you can drag and drop the button to a new position.

  3. How to access to Calculator Lite settings?

    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.

  4. How do I enter negative numbers?

    To change addon's settings click on the toolbar button -> scroll to the bottom of the page -> click on settings

  5. 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 % =.

  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 =.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. How to install Calculator Lite in your Firefox?

    To install Calculator Lite, head to Mozilla Store and click on "Add to Firefox" button.

  12. How to uninstall Calculator Lite from your Firefox?

    To uninstall Calculator Lite go to Firefox -> Add-ons -> Extension Name, then press Uninstall button.

Matched Content


Please keep reviews clean, avoid the use of improper language and do not post any personal information.
  • <a> Defines an anchor.

    Example: <a href="">a sample link</a>

  • <pre><code> Syntax Highlighting (Supported languages: Bash, JSON, HTML, JavaScript, and CSS).

    Example: <pre><code class="javascript">var foo = 'bar';</code></pre>

  • <strong> Defines bold text
  • <blockquote> Defines a long quotation
  • <caption> Defines a table caption
  • <cite> Defines a citation
  • <em> Defines italic text
  • <p> Defines a paragraph
  • <span> Defines a section in a document
  • <s> Defines strikethrough text
  • <strike> Defines strikethrough text
  • <u> Defines underlined text
  • <br> Defines a single line break; can be used alone and don't need an ending tag

What's new in this version

Change Logs:
    Last 10 commits on GitHub
    Hover over a node to see more details

    Need help?

    If you have questions about the extension, or ideas on how to improve it, please use the "Contact Developer" link above. Don't forget to search through the bug reports first as most likely your question/bug report has already been reported or there is a workaround posted for it.

    Recent Blog Posts on