 # Old School Calculator

Old School Calculator is a scientific calculator doing plain and simple math. Just input a formula as you would write it down.

The calculator comes with decimal, sexagesimal, exponential and fractional displays. It performs arithmetic, trigonometric and logarithmic functions. It knows about permutations, combinations and coordinate conversion.

...and it stores up to 7 numerical results!

### Really simple input

Old School Calculator knows about precedence rules.

Example: 10 + 2×6 - 15 ÷ (1 + 2) = 17

input display
1 0 + 10. +
2 × 6 - 22. -
1 5 ÷ ( ( 0.
1 + 2 ) 3.
= = 17.

The following examples use a shorter notation.

Instead of 10.25 you would type 10.25.

Old School Calculator accepts algebraic (infix) and old-style input methods. You can set the input method to be used on the settings page (gear in the top right corner).

An example with algebraic (infix) input method: √2 ÷ cos -45° = 2

2÷cos45+/-== 2.

The same example with old-style input method: √2 ÷ cos -45° = 2

2÷45+/-cos== 2.

### Number input

Category Example Input
rational numbers 0.3 .3 or 0.3
negative numbers -4.7 4.7+/-
exponential notation 3×102 (=300) 3EXP2
-5.2×103 (=-5200) 5.2+/-EXP3
-8.3×10-4 (=-0.00083) 8.3+/-EXP4+/-
pi π (=3.141592653...) EXP
fractions 2/3 (=0.666666...) 2a b/c3
5 1/4 (=5.25) 5a b/c1a b/c4
degrees 5° 20' 30" (=5.341666...) 5° ' "20° ' "30° ' "

### Functions 1

argumentfunction

For these functions you enter the argument followed by the function key.

Function Example Input Display
1/x Reciprocal 2-1 = 0.5 21/x= 0.5
x2 Square 32 = 9 3x2= 9.
x! Factorial 3! = 6 3SHIFTx!= 6.

### Functions 2

Old School Calculator comes with 2 input methods: algebraic (infix) and old-style. You can set the input method to be used on the settings page (gear in top right corner).

### algebraic (infix) input method

functionargument

Modern scientific calculators often use algebraic (infix) input method.

For these functions you press the function key followed by the argument if the input method is set to algebraic (infix).

Function Example Display
Square root √9 = 3
9=
3.
3 Cube root 3√27 = 3
SHIFT327=
3.
log Common logarithm log 100 = 2
log100=
2.
10x Powers of 10 102 = 100
SHIFT10x2=
100.
ln Natural logarithm ln 10 = 2.302585093
ln10=
2.302585093
ex Powers of e e2.302585093 = 10
SHIFTex2.302585093=
10.
sin
cos
tan
Sine, cosine, tangent sin 30° = 0.5
sin30=
0.5
sin-1
cos-1
tan-1
Arc
sine, cosine, tangent
asin 0.5 = 30°
SHIFTsin-1.5=
30.
hypsin
hypcos
hyptan
Hyperbolic
sine, cosine, tangent
sinh 5 = 74.20321058
hypsin5=
74.20321058
hypsin-1
hypcos-1
hyptan-1
Inverse hyperbolic
sine, cosine, tangent
sinh-1 74.20321058 = 5
SHIFThypsin-174.20321058=
5.

### old-style input method

argument function

Older, more basic calculators often use this input method.

For these functions you enter the argument first and then press the function key if the old-style input method is set.

function example display
Square root √9 = 3
9=
3.
3 Cube root 3√27 = 3
27SHIFT3=
3.
log Common logarithm log 100 = 2
100log=
2.
10x Powers of 10 102 = 100
2SHIFT10x=
100.
ln Natural logarithm ln 10 = 2.302585093
10ln=
2.302585093
ex Powers of e e2.302585093 = 10
2.302585093SHIFTex=
10.
sin
cos
tan
Sine, cosine, tangent sin 30° = 0.5
30sin=
0.5
sin-1
cos-1
tan-1
Arc
sine, cosine, tangent
asin 0.5 = 30°
.5SHIFTsin-1=
30.
hypsin
hypcos
hyptan
Hyperbolic
sine, cosine, tangent
sinh 5 = 74.20321058
5hypsin=
74.20321058
hypsin-1
hypcos-1
hyptan-1
Inverse hyperbolic
sine, cosine, tangent
sinh-1 74.20321058 = 5
74.20321058SHIFThypsin-1=
5.

### Functions with two arguments

argument 1functionargument 2

function example display
xy Powers 23 = 8
2xy3=
8.
x Roots 7√128 = 2
7SHIFTx128=
2.
nPr Permutations 6 nPr 3 = 120
6SHIFTnPr3=
120.
nCr Combinations 6 nCr 3 = 20
6SHIFTnCr3=
20.
R→P Rectangular to polar
coordinate conversion
x=3, y=4: 3 RP 4 = 5 (r), 53.13010235 (θ)
3SHIFTR→P4=
r = 5.
SHIFTx ↔ y θ = 53.13010235
P→R Polar to rectangular
coordinate conversion
r=2, θ=60: 2 PR 60 = 1 (x), 1.732050808 (y)
2SHIFTP→R60=
x = 1.
SHIFTx ↔ y y = 1.732050808

### Percentage calculations

You can set the kind of percentage calculation to be used on the settings page (gear in top right corner).

Modern scientific calculators often use this kind of percentage calculation. The advanced percentage calculation answers several questions easily.

19% of 120 = 22.8

120×19SHIFT% 22.8

Percentage of 80 represented by 25 = 31.25%

25÷80SHIFT% 31.25

19% add-on of 120 = 142.8

120×19SHIFT%+ 142.8

30% discount of 1000 = 700

1000×30SHIFT%- 700.

20 apples are added to a basket with 50 apples. What is the percentage of the new number of apples to the initial number of apples?: 140%

20+50SHIFT% 140.

If you got 50 EUR last week and 80 EUR this week, what is the percent increase?: 60%

80-50SHIFT% 60.

### Percentage calculations - simple

Basic calculators come often with this kind of percentage calculation.

example input display
200 + 19% = 238 200+19SHIFT%= 238.
238 - 19% = 192.78 238-19SHIFT%= 192.78
200 ÷ 50% = 2 200÷50SHIFT%= 2.
200 × 50% = 20000 200×50SHIFT%= 20000.

With your input we can further improve our services.

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# History

## Version 2.1

App Store 2011-07-15, Google Play Store 2011-08-14, BlackBerry App World 2011-08-18, webOS 2011-08-27.

• new: improber fractions.
• new Android: uses menu key and back key.
• new Android: changed icon.
• fix: random number, 3rd root.

## Version 2.0

App Store 2011-03-30, Google Play Store 2011-03-28.

• new: beautiful math display using the power of TeX (iPad iOS 4.2+, Android tablets 1280x768).
• new: polar and rectangular coordinate conversion.
• new: register exchange.
• new: optimized for Android tablets.

## Version 1.5.2

App Store 2011-02-22.

• new: inserts multiplication sign automatically: "4" "sin" => "4 × sin".
• fixed bugs: fractions and degrees display.

## Version 1.5.1

App Store 2011-01-21, Google Play Store 2011-01-29.

• fixed bug: help opens in new window.
• fixed bug: key click for all keys.

## Version 1.5

App Store 2011-01-18.

• new: algebraic (infix) and old-style input methods.
• new: simple and advanced percentage calculations.
• improved display.
• new: user guide.
• new: feedback form.

## Version 1.4

App Store 2010-11-28.

• new: key clicks.
• changes for iOS 4.2

## Version 1.3

App Store 2010-11-04.

• new: Shows entered expressions.
• improved display.

## Version 1.2

App Store 2010-10-19.

• new: fractions