How To Write Calculator Test Cases? With Sample Test Cases

Calculator testing seems quite simple but you can easily get buried in the details. Calculator test cases can run from the UI, basic calculations, and more complex numerical operations. 

Writing test cases uses the same basic concepts for developing tests for any application. Calculators appear frequently on questions on a software testing exam or interview. Why? Because calculator testing is far more involved than it appears and being able to bring out all the necessary tests is a good exercise for new or green QA testers. 

As with any testing, the first step is to analyze the requirements or acceptance criteria. Use the suggestions that follow to fill in any gaps in your requirements or to supplement your testing effort as needed. Be sure to have your peers or other testers perform a test case review to ensure no scenarios are missed. 

Basic Functionality Test Cases For Calculator

Test cases for calculators include tests for basic functionality that include the following basic functional test scenarios:

●      Add one or more numbers and verify the calculated result when you hit =.

●      Subtract one or more numbers and verify the calculated result when you hit =.

●      Multiply one or more numbers and verify the calculated result when you hit =.

●      Divide a few numbers and verify the calculated result when you hit =.

●      Verify the AC and C buttons clear the result screen when you hit =. 

●      Add, subtract, and multiply using a negative number when you hit =.

●      Add, subtract, multiply, and divide by numbers with decimals when you hit =.

●      Use the MR, M-, and M+ and confirm the memory returns accurate values. 

●      Test the CE button clears the last entry. 

Functional Test Cases For A Calculator

Our functional test cases for calculators expand on the basic testing we previously discussed. For functional tests, we want to verify the calculator follows standard mathematical logic. 

Testing functionality includes the following test scenarios:

• Add, subtract, multiply, and divide negative numbers. 
•  Add, subtract, multiply, and divide one or more positive numbers with one or   more negative numbers. 
• Add, subtract, multiply, and divide using 0 (zero).
• Do a few calculations and then hit the AC (All Clear) button or MC (memory clear) button. Do a new calculation, and verify the old values are not used. 
• Calculate a percentage with various positive and negative numbers. 
•  Calculate a square root with various positive and negative numbers. 

Boundary Conditions Test Cases For Calculator

Boundary value testing involves testing the boundary values, both positive and negative. Check the calculator requirements, if any, to see if there are maximum and minimum values defined. Each test case for the calculator needs to include a consideration of valid and invalid boundary values. 

Test the following boundary value conditions including:

• Calculations with 0 (zero)
• Calculations with maximum values. Ex.) 999,999,999 x 2 and verify the result is truncated like 2e9
• Calculations with minimum values. Ex.) 0.0.00 multiplied by 1 = 0
• Calculations with negative values and zero. 
• Verify the battery life, if applicable, lasts the designated time. 
• If solar, verify the battery charges in sunlight if applicable. 

Negative Test Cases For Calculator

Negative test cases include test scenarios in which the tester attempts to break the calculator functionality or find edge cases that fail to compute as expected. Consider physical tests if the calculator is a separate device. For computer apps, test for connectivity issues when the device battery is low or the device is charging. 

Negative test cases include:

• For computer-based calculator apps, determine if the app hangs during multiple or long computations. 
•  Verify the app’s response when holding down a key for long periods. 
•  Verify how the calculator functions on low power source conditions. 
• Attempt to launch a computer-based calculator in a second session. 

Test Cases For Advanced Scientific Calculator

Advanced scientific calculators should perform all the basic tests described above. In addition, you’ll need to test the following options:

●      Verify the scientific notation.

●      Use physical constants in a calculation.

●      Calculate one or more exponential values. 

●      Calculate one or more cosine functions. 

●      Calculate one or more logarithms. 

●      Calculate the square root.

●      Calculate a number’s sine.

●      View different options within the scientific notation display. 

●      Verify the order of operation or BODMAS.

Software-Based Calculator Test Cases

Most software-based calculators are more simplistic versions with standard mathematical operations. 

• Add one or more numbers and verify the calculated result when you hit =.
• Subtract one or more numbers, and verify the calculated result when you hit  =.
• Multiply one or more numbers and verify the calculated result when you hit =.
• Divide a few numbers and verify the calculated result when you hit =.
• Verify the AC and C buttons clear the result screen when you hit =. 
• Add, subtract, and multiply using a negative number when you hit =.
• Add, subtract, multiply, and divide by numbers with decimals when you hit =.
• Use the MR, M-, and M+ and confirm the memory returns accurate values. 
• Test the CE button clears the last entry. 
• Add, subtract, multiply, and divide negative numbers. 
•  Add, subtract, multiply, and divide one or more positive numbers with one or more negative numbers. 
•  Add, subtract, multiply, and divide using 0 (zero).
• Do a few calculations and then hit the AC (All Clear) button or MC (memory clear) button. Do a new calculation, and verify the old values are not used. 
• Calculate a percentage with various positive and negative numbers. 
• Calculate a square root with various positive and negative numbers.
• Verify the UI functions in standard ways for computer apps. 
• Test whether the user can maximize or minimize the app. 

Usability Test Cases For A Calculator

Usability testing ensures the customer can use the calculator with all functions. For usability testing of a calculator test:

●      Button spacing.

●      Button location.

●      Sizing up and sizing down.

●      Test with a device connected to wifi or being charged

●      Test with a device not connected to wifi

●      Test the installation of the app

●      Verify the viewable display is present. 

●      Verify users can open and close the app without error. 

●      Verify users can shrink or expand the window. 

●      Verify users can download 

●      Test to verify the app does not hang when in use. 

User Interface Test Cases For Calculator

For online calculators, test the interface as you would usability (above). For separate calendar devices, add the following tests:

• Brand or logo.
•  Color, shape, height, and length of the device.
• Determine if the visible screen is easy to view. 
• Confirm the size of the buttons is accurate. 
•  Verify the calculator can be turned OFF or ON. 
•  Verify the print function results in a hard copy print or electronic document that is readable and accurate. 
•  Confirm the screen and buttons are visible in a variety of light-level conditions. 

Manual and Automated Test Cases

Use the table below to create either or both manual and automated test cases. 

Manual Calculator Tests that can be	Automated Calculator Tests
Basic functions include:  ●      Add one or more numbers, verify the calculated result when you hit =. ●      Subtract one or more numbers, verify the calculated result when you hit =. ●      Multiply one or more numbers, verify the calculated result when you hit =. ●      Divide a few numbers, verify the calculated result when you hit =. ●      Verify the AC and C buttons clear the result screen when you hit =.  ●      Add, subtract and multiply using a negative number when you hit =. ●      Add, subtract, multiply, and divide by numbers with decimals when you hit =. ●      Use the MR, M-, and M+ and confirm the memory returns accurate values.  ●      Test the CE button clears the last entry.	Basic functions include:  ●      Add one or more numbers, verify the calculated result when you hit =. ●      Subtract one or more numbers, verify the calculated result when you hit =. ●      Multiply one or more numbers, verify the calculated result when you hit =. ●      Divide a few numbers, verify the calculated result when you hit =. ●      Verify the AC and C buttons clear the result screen when you hit =.  ●      Add, subtract and multiply using a negative number when you hit =. ●      Add, subtract, multiply, and divide by numbers with decimals when you hit =. ●      Use the MR, M-, and M+ and confirm the memory returns accurate values.  ●      Test the CE button clears the last entry.
Boundary Testing scenarios include:  ●      Calculations with 0 (zero) ●      Calculations with maximum values. Ex.) 999,999,999 x 2 and verify the result is truncated like 2e9 ●      Calculations with minimum values. Ex.) 0.0.00 multiplied by 1 = 0 ●      Calculations with negative values and zero.  ●      Verify the battery life, if applicable, lasts the designated time.  ●      If solar, verify the battery charges in sunlight if applicable.	Functional Testing scenarios include:  ●      Add, subtract, multiply, and divide negative numbers.  ●      Add, subtract, multiply, and divide one or more positive numbers with one or more negative numbers.  ●      Add, subtract, multiply, and divide using 0 (zero).. ●      Do a few calculations and then hit the AC (All Clear) button or MC (memory clear) button. Do a new calculation, and verify the old values are not used.  ●      Calculate a percentage with various positive and negative numbers.  ●      Calculate a square root with various positive and negative numbers.
Negative test scenarios include:  ●      For computer-based calculator apps, determine if the app hangs during multiple or long computations.  ●      Verify the app’s response when holding down a key for long periods.  ●      Verify how the calculator functions on low power source conditions.  ●      Attempt to launch a computer-based calculator in a second session.	Advanced Scientific calculation tests including:  ●      Verify the scientific notation. ●      Use physical constants in a calculation. ●      Calculate one or more exponential values.  ●      Calculate one or more cosine functions. ●      Calculate one or more logarithms.  ●      Calculate the square root. ●      Calculate a number’s sine. ●      View different options within the scientific notation display.
Usability test scenarios include:  ●      Button spacing. ●      Button location. ●      Sizing up and sizing down. ●      Test with a device connected to wifi or being charged ●      Test with device not connected to wifi ●      Test the installation of the app ●      Verify the viewable display is present.  ●      Verify users can open and close the app without error.  ●      Verify users can shrink or expand the window.  ●      Verify users can download ●      Test to verify the app does not hang when in use.	Software app tests include: ●      Add one or more numbers, verify the calculated result when you hit =. ●      Subtract one or more numbers, verify the calculated result when you hit =. ●      Multiply one or more numbers, verify the calculated result when you hit =. ●      Divide a few numbers, verify the calculated result when you hit =. ●      Verify the AC and C buttons clear the result screen when you hit =.  ●      Add, subtract and multiply using a negative number when you hit =. ●      Add, subtract, multiply, and divide by numbers with decimals when you hit =. ●      Use the MR, M-, and M+ and confirm the memory returns accurate values.  ●      Test the CE button clears the last entry.  ●      Add, subtract, multiply, and divide negative numbers.  ●      Add, subtract, multiply, and divide one or more positive numbers with one or more negative numbers.  ●      Add, subtract, multiply, and divide using 0 (zero).. ●      Calculate a percentage with various positive and negative numbers.  ●      Calculate a square root with various positive and negative numbers.
User interface testing scenarios include:  ●      Brand or logo. ●      Color, shape, height, and length of the device. ●      Determine if the visible screen is easy to view.  ●      Confirm the size of the buttons is accurate.  ●      Verify the calculator can be turned OFF or ON.  ●      Verify the print function results in a hard copy print or electronic document that is readable and accurate.  ●      Confirm the screen and buttons are visible in a variety of light-level conditions.	Error condition testing: Check for error conditions specific to the calculator and test accordingly.
Software-based app tests include:  ●      Do a few calculations and then hit the AC (All Clear) button or MC (memory clear) button. Do a new calculation, and verify the old values are not used. ●      Verify the UI functions in standard ways for computer apps.  ●      Test whether the user can maximize or minimize the app	BODMAS test cases for calculator.

Automation with Testsigma

Use TestSigma to automate your calculator tests. Testers with various levels of experience can quickly create an automated suite of calculator tests using TestSigma. 

You may be able to automate nearly all your tests outside of usability and interface testing with an automated tool like TestSigma. 

Learn more about automating your tests with Testsigma

Frequently Asked Questions

What are some important test cases for a calculator application?

First, test all requirements for the calculator. Next, review the calculator functionality for any missing or incomplete requirements. The most important tests are listed in the basic and functional test scenario sections in this article. 

What types of Calculator Test Cases should you include in your regression suite?

All critical or high-priority test cases should be part of any regression suite of calculator test cases. Additionally, consider adding test scenarios listed in this article within the manual and automated test table.  

What if I don’t have any requirements for testing a calculator?

Use the lists above to generate ideas. You can also compare the calculator you are testing to the standard calculators available in Microsoft Windows or Apple computers, or phones. Compare them with your applications as a baseline.