[Â HomeÂ ] [Â UpÂ ]
 Welcome to the Teachers' Choice Software web site. Our FREE on line mathematics 'How-To' library is open 24 hours a day.Â  The ever-growing library now has 71 helpful topics, and every topic includes a free download!

You can type algebra expressions, equations and values into Algematics exactly as they appear in your text book or study notes. This topic explains the easy formula language that makes this possible.

### Â To enter data (equations or inequalities or expressions) into Algematics:

1. you start at the Algematics main window, then
2. press the F3 key. (Or the toolbar button.) to display the data entry dialog box:

You type your equations and expressions into the lower edit box, while the upper edit box is for comments, headings or other descriptive text.

These are the rules for typing numbers, equations and expressions into the lower edit box...

### Entering Numbers

Integers
The range of integer values allowed is from
-18446744073709551615 to 18446744073709551615Â

Fractions
To enter a fraction, type two numbers as a ratio, with a colon : character between them. For
example, 3:4 for three quarters, 5:8 for five eighths. The numbers in the ratio cannot be outside of the range for integers.

Â Decimals
When you enter decimal numbers, they are represented internally as ratios. If converting the decimal to a ratio results in numbers outside of the integer range, then an error will occur and you will not be able to enter the decimal number. You can correct the error by using less decimal places.

### Entering Expressions

Variables
All lower case: '
a' to 'z' and upper case 'A' to 'Z' letters are allowed as variables.
The question mark: '
?' can also be used as a variable.Â

Greek letters
To make Greek letters, like
p, q, f, S, D etc., put a single quote character immediately before the letter. eg:

'pÂ  gives p
'qÂ
gives
q
'fÂ Â
gives f
'SÂ
gives S
'DÂ
gives D

Brackets
Only 'round' brackets: '
(' and ')' can be used as brackets in Algematics.
(Square brackets are used for powers as described below.)

Powers
Type the index of powers in square brackets, eg
x[2] means x²

Â Roots and Surds
Any type of roots or surds may be entered by using the power notation described above with a fraction for the index. For example, to enter the square root of x, type:
x[1:2]Â  Roots can be displayed as either a power or with a root sign.

Â Rational Expressions
To enter rational expressions, you must be very careful to make sure that the denominator is constructed properly.
For example, to enter the rational expression:

you could type:

(abc)/(def ),Â
abc
/(def ),
orÂ

abc
/d/e/f.

All of these expressions mean that the factors 'a', 'b' and 'c' are divided by all of the others: 'd', 'e', and 'f'. You will usually use the first method:

(abc)/(def)

Often Algematics will create expressions that look like the third:

abc/d/e/f

Â This expression:

abc/def

would be wrong, because only 'd' is in the denominator. ( What it really means is: abcef /d )

### Entering Equations

Enter equations as two expressions with anÂ  = symbol between them. Only one = symbol is allowed per equation.

Â eg:Â  a + b + c = d + e + f

### Entering Inequalities

Inequalities are entered in the same way as equations, but special symbols are used instead of the equal sign:

Â

' > ' for 'greater than'
'
< ' for 'less than'
'
>= ' for 'greater than or equal to'Â  (Enter a ' > ' character, then an ' = ' character.)
'
<= ' for 'less than or equal to' (Enter a ' < ' character, then an ' = ' character.)
'
<> ' for 'not equal to' (Enter a ' < ' character, then a ' > ' character.)

Â ' >= ' ,Â  ' <= 'Â  and ' <> ' ,will display properly on the screen as 'greater than or equal to' ,Â  'less than or equal to' , and 'not equal to' symbols respectively.

### Shortcut Buttons

These short cut buttons in the data entry dialog box simplify entry of complicated expressions with powers, roots, brackets and quotients.Â

For example, to make a rational expression in the 'maths box', use the button...

If there is no text selected in the 'maths box', then click to insert: '( )/( )' at the cursor position. Now you can type the numerator and denominator in the brackets.

If there is text selected, then click to make the selected text the numerator and you can now type in the denominator. Â

For example, you want to divide:Â  2x[2] + 3x + 4Â  by 3x + 2 Â
To do this, select
2x[2] + 3x + 4 in the 'maths box', then click
. Â
You will now have:
(2x[2] + 3x + 4)/( ) Â

Now simply type the denominator in the right hand brackets:
(2x[2] + 3x + 4)/(3x + 2)

Â