Mathematical Software. Mathematical Research. Mathematical Education. Tvalx Products.
Household Calculator is a general purpose calculator which combines the simplicity in use and the power in calculation. It handles main arithmetic operations with two operands: addition, subtraction, multiplication, division; and complex formulas with unlimited number of operations and operands. For example, you can type in the Edit Window a formula such as ((12.55+10.05+8.45+17.35)/30)*0.7-(13.45+15.76+2.05)*0.33 . Ergonomic design allows easily navigation through the controls and data entry using both a mouse and/or a keyboard.
The Household Calculator has three windows or boxes: Edit Window, Result Window, and History Window. In the Edit Window you enter formulas using buttons and a keyboard. When you use a keyboard, you can use all standard rules of text editing. The most convenient is the use of a numerical pad on the right of a standard keyboard. Buttons also provide full functionality of the Household Calculator. If you make a mistake while typing a formula, such as square root of a negative number, you just get a message in the Result Window that the formula is unclear. The Household Calculator tries to handle all possible ambiguities, following the standard mathematical rules. For example, formula 3/-4 - 5*2 will be treated as 3/(-4) - (5*2) . If you want to be completely sure in the result, use parentheses.
A result number in the Result Window can be copied into the Edit Window by clicking the Result button. Sometimes it is useful during calculations. For example factorial button is absent, but you can easily calculate 10! by typing formula 1*2*3*4*5*6*7*8*9*10 or by series 2*3, =, Result, *4, =, Result, *5, =, Result, *6, =, Result, *7, =, Result,*8, =, Result, *9, =, Result, *10, =, imitating "old style calculators".
Calculation History Window has unlimited length. Use a scroll bar to navigate the window with log history. You can save the calculation history into text file or print it. Before you save, you can change size and style of the font in the History Window.
There are four standard arithmetic operations buttons : + - * / . Clicking button "=" triggers calculation. If you typing into Edit window from keyboard then do not use Enter key for triggering calculation. It is not supported in Advanced Calculator.
Plus and minus denote in fact two operations. Binary operation with two operands is usual addition and subtraction. The other is unary operation. For example, minus in 2-1 denotes binary operation of subtraction. But in 3*(-2) minus denotes unary operation. Thus we distinguish unary and binary operations by context. For example, n 1+-2 = 1+(-2) = -1, 1+-+-+-2 = 1+(-(+(-(+(-2)))) = 1-2 = -1 .
Multiplication and division have equal precedence and have higher precedence than addition and subtraction. Thus in formula 1/2+3*4 first calculation is 1/2=0.5, second 3*4=12 and third is 0.5+12=12.5 .
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