Functions of an office calculator – TAX, margin MU, GT and Check & Correct
2026-08-26On the keyboard of a more advanced office calculator, there are often many more buttons than just numbers and basic mathematical operations. Labels such as TAX, MU, GT, MRC, COST, SELL, MARGIN, or Check & Correct may initially seem unclear, but in practice, they can significantly speed up daily work.
This is especially true for those working in trade, services, offices, accounting, maintenance, or their own business, where prices, percentages, taxes, and margins are regularly calculated.
See available office and pocket calculators at Hurtownia Kurant
Why is an office calculator still useful?
A calculator on a phone or computer works well for single operations. However, for regular work with numbers, a separate device can be much more convenient. Large keys, a clear display, and functions available directly under one button allow for faster calculations and reduce the need to constantly reach for a phone.
The differences between calculators are not only about size or the number of digits on the screen. Depending on the model, special functions for commercial, tax, and financial calculations may be available.
What does TAX mean on a calculator?
TAX is a function designed for quick calculations related to tax. In calculators equipped with this function, a specific rate can be saved, and then using the appropriate keys, it can be added to or subtracted from values.
In practice, this solution can be useful for frequently converting net and gross prices. Instead of performing a full percentage calculation each time, the calculator uses the previously saved value.
The TAX function can thus facilitate work in:
- stores and wholesalers,
- service points,
- offices,
- maintenance,
- small businesses and entrepreneurship.
What does MU mean on a calculator?
The designation MU comes from the English term Mark Up. This function is used for calculations related to margin and markup.
It is particularly useful for those who frequently work with purchase and selling prices. Instead of performing several consecutive operations, a suitably equipped calculator allows for quicker calculation of the value needed when setting the selling price.
Therefore, a calculator with a margin function can be a good choice for a seller, store owner, wholesaler, or service point.
Margin and markup – are they the same?
In everyday language, the terms margin and markup are often used interchangeably, but mathematically they mean something different.
Markup refers to the purchase price. If a product costs 100 PLN, and we add a markup of 30%, we get a selling price of 130 PLN.
Margin, on the other hand, defines what part of the selling price is the difference between the selling price and the purchase price. In the above example, the difference is 30 PLN, but it does not constitute 30% of the selling price.
When frequently performing such calculations, dedicated calculator functions help avoid mistakes resulting from manually applying several consecutive formulas.
COST, SELL, and MARGIN – calculator for commercial calculations
Some more advanced calculators have separate keys for COST, SELL, and MARGIN.
These designations refer to:
- COST – cost or purchase price,
- SELL – selling price,
- MARGIN – margin.
If two of these values are known, a suitably equipped calculator can help determine the third. This solution is primarily designed for commercial applications.
What does GT mean on a calculator?
GT is an abbreviation for Grand Total, meaning the total sum. This function allows for remembering the results of consecutive operations and then displaying their total value.
This can be useful, for example, when calculating the values of several separate groups of products and at the end, we want to obtain their total sum.
GT should not be confused with the standard memory of a calculator. It is a separate function specifically designed for summing consecutive results.
What are M+, M-, MR, MC, and MRC for?
Memory buttons are found even in relatively simple calculators. They allow you to save a specific value and use it in subsequent operations.
- M+ – adds the displayed value to memory,
- M- – subtracts the displayed value from memory,
- MR – recalls the value saved in memory,
- MC – clears memory,
- MRC – depending on how it is used, allows recalling or clearing memory.
Memory is particularly convenient when performing several related operations. There is no need to write down intermediate values on paper or re-enter them into the calculator.
Why does a calculator need a second memory?
Some models are equipped with an additional independent memory, designated, for example, as MII. It allows for storing more than one value simultaneously.
This can be convenient during more complex calculations when one number must remain saved while operations are performed using another value at the same time.
Check & Correct – checking previous calculations
One of the more interesting functions available in more advanced calculators is Check & Correct.
The calculator remembers each entered operation, allowing you to review individual stages of the calculation later. If a mistake was made while entering a long string of numbers, it is not always necessary to start the entire calculation from the beginning.
Depending on the model, the memory can cover several dozen or over a hundred consecutive steps.
This function is particularly useful for:
- summarizing many items,
- checking long calculations,
- controlling entered values,
- working with a larger number of documents or prices.
Auto Replay – automatic replay of operations
The calculation control function may be linked to the Auto Replay function. It allows for automatically reviewing previously performed operations.
Instead of manually going through each saved step, the calculator presents the memorized operations sequentially. This can facilitate checking the correctness of longer calculations.
What do the switches 0, 2, 3, 4, and F mean?
In larger office calculators, there is often a switch that determines the number of decimal places.
When selecting value 0, the result is displayed without decimal places. Settings of 2, 3, or 4 allow you to specify the appropriate number of digits after the decimal point.
The position F usually indicates the free decimal place mode, in which the calculator does not enforce a specific number of digits after the decimal point.
This function is particularly useful when regularly performing price and financial calculations.
What is the rounding switch for?
In some calculators, next to the setting for the number of decimal places, there is also a switch for the method of rounding the result.
This allows you to specify whether the calculator should use standard rounding, rounding down, or another method provided by the specific model.
This way, there is no need to manually correct the result after each operation.
Why are the keys 00 and 000 useful?
The buttons 00 and 000 may seem like a minor addition, but when frequently entering larger numbers, they significantly speed up work.
Instead of pressing the zero key three times, one press of the 000 key is sufficient. This is particularly important when entering a large number of financial values daily.
8, 10, 12, 14, or 16 digits – which display to choose?
The number of digits determines the maximum length of the value that the calculator can comfortably display.
For basic applications, an 8- or 10-digit calculator is usually sufficient. One of the most versatile solutions for a company is a 12-digit calculator.
Models with 14 and 16 digits are intended for users working with larger values or expecting a more advanced office device.
Battery, solar, or dual power?
Calculators can use batteries, solar panels, or both sources simultaneously.
Battery-solar power is a universal solution. With adequate lighting, the device can use the solar panel, while the battery allows operation in less favorable lighting conditions.
For occasional use, simple battery-powered calculators work well, while solar models are convenient primarily when working at a well-lit station.
Which calculator to choose for a store or service point?
If the calculator is primarily for simple calculations, percentages, or giving change, the most advanced model is not always necessary.
However, for regular work with prices, it is worth paying attention to functions such as:
- 12-digit or larger display,
- calculating percentages,
- MU – calculating margin,
- TAX – quick tax calculations,
- COST / SELL / MARGIN,
- GT – grand total,
- memory M+, M-, and MRC,
- Check & Correct,
- selection of decimal places,
- battery-solar power.
Not every user needs all these functions. It is therefore worth first determining which calculations are performed most frequently and only then choosing the appropriate calculator.
ELEVEN and Citizen calculators at Hurtownia Kurant
Our offer includes pocket and office calculators from ELEVEN and Citizen – from simple models for basic operations to more advanced calculators equipped with functions useful in trade and daily business work.
Recently, the ELEVEN calculator range has been expanded with new models. At the same time, we have introduced new, lower prices for many products.