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The COVID-19 social distancing impact calculator was developed 100% @home.2 Formula.This formula takes known oxygen and air flows and calculates the FiO 2.FiO 2 = (Air flow x 0.21) + (Oxygen flow x 1.0) Total Flow.Note: –Air flow and oxygen flow must use the same units –Remember that the oxygen in room air contributes to the FiO 2 as well! This will help you remember the formula. Our new Combat Training Skill Calculator can help you determine how many monster kills will get you to your target level. OldSchool.tools is an Old School RuneScape tools & calculators site. Our new Combat Training Skill Calculator can help you determine how many monster kills will get you to your target level. OldSchool.tools is an Old School RuneScape tools & calculators site. The expression '5 mod 2' would evaluate to 1, because 5 divided by 2 leaves a quotient of 2 and a remainder of 1. Enter a number, then click on MOD, then enter another number, then click equals. Log Log is the logarithm (exponent) on base 10 of a number. The log of a number of 45 is log 45 and equals 1.653212. This Calculator was written by McSwindler.Thanks to Oblivion590, Helcaterian, Maxwaterman, Fern1970, Hans980, and Benmarchant for corrections. This Calculator was entered into the database on Fri, Feb 17, 2006, at 10:39:43 PM by MrStormy, and it was last updated on Wed, Nov 15, 2017, at 02:02:19 AM by Numerous One.
- Most common
- Atomic-nuclear
- Electromagnetic
- Physico-chemical
- Universal
- X-Ray
Help and Tips
Color Coding
Simple number or constant.
Action that involves two numbers (i.e. 6+2).
Action that requires one number (i.e. 40%).
Clears something.
Gives a result.
Actions about the calculator or the tape.
Number formating actions fractions and scientific notation.
Keyboard
You can use your numeric keypad to insert numbers along with the keys 'enter', 'equals', 'backspace', 'delete', as well as the + - * / keys.
Tape and Tape Buttons
All calculations are saved on the tape. Click on any number or operator on the tape and change it at any time. Hit equals and the new result will appear.
You can use the print button to print out the tape.
Clearing Buttons
Clear button clears the last input.
All clear button clears the calculator, tape, and resets any functions.
Memory clear button clears the memory.
Memory Buttons
Memory recall button retrieves the number you have in memory and places it in the display field.
Memory plus button adds the number displayed to the contents of the memory.
Memory minus button subtracts the number displayed from the contents of the memory.
Function Buttons
Percent button is used to find the percentage of a number. Enter the percentage amount, click the % button, then enter the number you want the percentage of, and then click equals. i.e. 20% 125 = 25 where 25 is 20% of 125. Note: The percent function will also work if you enter the number first and then the percentage you want i.e. 125 %20 = 25.
Fractions
To enter a fraction of the form 3/4. Click a number and then click fraction bar, then click another number.
You can use fraction space button to create a number of the form 5 3/4. Enter a number, then click fraction space, click another number and then click on the fraction bar button, lastly enter another number.
Decimal format button and Fraction format button work as pair. When you choose the one the other is switched off.
Decimal format button is used for all decimal work. Also to change a fraction of the form 3/4 to the decimal 0.75, or a fraction of the form 7/4 or a mixed number of the form 1 3/4 to the decimal 1.75. Click on the decimal format button, enter a fraction or mixed number, then click equals. If the fraction or mixed number is only part of the calculation then omit clicking equals and continue with the calculation per usual. i.e. 3/4 DEC x 6 =.
Fraction format button is used to work with all fractions. Also to change a decimal of the form 0.5 to the fraction 1/2, or change a decimal of the form 1.75 to a mixed number of the form 1 3/4 or to the fraction 7/4, or a fraction of the form 7/4 to the mixed number 1 3/4. Click the fraction format button, enter a decimal, click equals and then click on a fraction form and then click equals. If the fraction of decimal is part of a calculation, omit clicking equals and continue with the calculation.
Proper fraction button and Improper fraction button work as pair. When you choose the one the other is switched off.
Proper fraction button is used to change a number of the form of 9/5 to the form of 1 4/5. A proper fraction is a fraction where the numerator (top number) is less than the denominator (bottom number).
Improper fraction button is used to change a number of the form of 1 4/5 to the form of 9/5. An improper fraction is a fraction where the numerator (top number is greater than or equal to the denominator (bottom number).
Views
You can use the view menu button to add fuctionality to the standard calculator.
You can add a scientific keypad to calculate logarithms, a trigonometric keypad to calculate angles, and a fraction keypad to form, add, subtract, divide, and multiply fractions.
You can also choose to hide the tape.
Constants
You can use the constants menu button to choose between most common constants, atomic and nuclear constants, electromagnetic constants, physico-chemical constants, universal constants, and x-ray constants.
Scientific
X^2 is the square of a number or a number times itself. Enter a number, then click x^2.
X! is x factorial. X is a whole number greater than 0. A number in the form 4! is 4x3x2x1 or 24. Enter a number, then click x!
1/x is the reciprocal of a number and x cannot be zero. Enter a number of the form 0.2 and get 5. Enter a number, then click 1/x.
This button is used to inverse x and y.
Base operation is used to set a number as base (i.e. decimal or hexadecimal system). Enter a number, then click base.
The modulo operation finds the remainder after division of one number by another. The expression '5 mod 2' would evaluate to 1, because 5 divided by 2 leaves a quotient of 2 and a remainder of 1. Enter a number, then click on MOD, then enter another number, then click equals.
Log is the logarithm (exponent) on base 10 of a number. The log of a number of 45 is log 45 and equals 1.653212. Enter a number, then click on Log.
In is natural log or the logarithm (exponent) on base e of a number. The In of a number of 45 is In 45 and equals 3.806662. Enter a number, then click on In.
Lg2 is the logarithm (exponent) on base 2 of a number. The log of the number 45 base 2 is lg2 45 and equals 5.49185. Enter a number, then click on Lg2.
Lgy^x you can use this to raise a logarithm to higher power.
Y^x you can use this to raise a number to higher power. Enter a number, then click y^x, then enter another number.
You can use the x-root-of-y button to find any root of a number. Enter a number (y), then click x-root-of-y button, then enter another number (x), and then click equals.
10^x is 10 raised to the x power (exponent). A number in the form of 10^4 is 10000. Enter a number (exponent), then click 10^x.
e^x is e raised to the x power (exponent). A number in the form e^4 is 54.5982. Enter a number (exponent), then click e^x.
2^x is 2 raised to the x power (exponent). A number in the form 2^4 is 16. Enter a number, then click 2^x.
The number e is an important mathematical constant that is the base of the natural logarithm. It is approximately equal to 2.71828.
The number pi is a mathematical constant, the ratio of a circle's circumference to its diameter, approximated as 3.14159.
Phi represents the golden ratio, two quantities are in a golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. It is approximately 1.61803.
You can use the scientific notation button to handle very large numbers, this system makes use of 'powers of 10', raising 10 to whatever value you need. You can get either really big numbers by using positive powers like 10^5=100000. Or you can get really small numbers by using negative powers like 10^-5=0.00001. e stands for exponent and is used to represent 'times 10 raised to the power of' (x 10^n). For example, if you want the number 100000000 as a scientific notation, you enter 10, then click SN, then 7, and then equals (10eX10^7=100000000).
You can use the parentheses pair to group terms. Every parenthesis you open is numbered, parenthesis levels are indicated by a number in the display box next to the parentheses buttons. This way you can easily know how deep in a parenthesis you are, when the expression is complete there are no parenthses left in the display box. This is used for groupings of the form 4+(9x(15-7)+6). Click the open parenthsis button, enter terms, then click the close parenthesis button.
Trigonometric
You can choose between Gradian, Radian, and Degree unit modes, when you choose one the others are switched off.
The gradian (also known as gon) is a unit of plane angle. 1 grad = 1/400 tr = pi/200 rad = 9/10 deg.
The radian is the standard unit of angular measure. 1 rad = 1/2pi tr = approx. 57.296 deg = approx. 63.662 grad.
The degree is a unit of measurement of plane angle. 1 deg = 1/360 tr = pi/180 rad = 10/9 grad.
Sine finds the ratio y/r value of an angle. Enter a number, then click sin.
Cosine finds the ratio x/r value of an angle. Enter a number, then click cos.
Tangent finds the ratio y/x value of an angle. Enter a number, then click tan.
Sinh is the hyperbolic sine or sinh value of an angle. Enter a number, then click sinh.
Cosh is the hyperbolic cosine or cosh value of an angle. Enter a number, then click cosh.
Tanh is the hyperbolilc tangent or tanh value of an angle. Enter a number, then click tanh.
Asin is arcsine or sin^(-1). It finds the angle between -90 degrees and 90 degrees inclusive or between -pi/2 and pi/2 inclusive, with this sine value. Enter a number, then click asin.
Acos is arccosine or cos^(-1). It finds the angle between 0 degrees and 180 degrees inclusive or between 0 and pi inclusive, with this cosine value. Enter a number, then click acos.
Atan is arctangent or tan^(-1). It finds the angle between -90 degrees and 90 degrees inclusive or between -pi/2 and pi/2 inclusive, with this tangent value. Enter a number, then click atan.
Ash is arc hyperbolic sine, arcsinh or sinh^(-1). It finds the angle with this sh or sinh value. Enter a number, then click ash.
Ach is arc hyperbolic cosine, arccosh or cosh^(-1). It finds the angle with this ch or cosh value. Enter a number, then click ach.
Ath is arc hyperbolic tangent, arctanh or tanh^(-1). It finds the angle with this th or tanh value. Enter a number, then click ath.
Calculator Tricks
Amusing things to do with a calculator.
Mind Reading
- Have someone pick a number between 1 and 9.
- Now have him use a calculator to first multiply it by 9, and then multiply it by 12,345,679 (notice there is no 8 in that number.).
- Have the person show you the result so you can tell him the original number he selected. How? If he selected 5, the final answer is 555,555,555. If he selected 3, the final answer is 333,333,333. The reason: 9 x 12345679 = 111111111. You multiplied your digit by 111111111. (By the way, that 8-digit number (12,345,679) is easily memorized: only the 8 is missing from the sequence.)
The 421 Loop
- Pick a whole number and enter it into your calculator.
- If it is even, divide by 2. If it is odd, multiply by 3 and add 1.
- Repeat the process with the new number over and over. What happens?
- The sequence always ends in the 'loop': 4.....2.....1.....4.....2.....1...
Example: Start with 13.
- 13 is odd, so we multiply by 3 and add 1. We get 40. ((13 times 3 = 39 + 1= 40))
- 40 is even, so we divide by 2. We get 20. ((40 div 2 = 20))
- 20 is even, so we divide by 2 and get 10.
- 10 is also even so we divide by 2 again and get 5.
- 5 is odd so we multiply by 3 and add 1. We get 16.
- 16 is even, so we divide by 2 and get 8.
- 8 is also even so we divide by 2 again and get 4.
- 4 is even so we divide by 2. We get 2.
- 2 is even, so we divide by 1 and get 1.
- 1 is odd, so we multiply by 3 and add 1. We get 4.
- 4 is even so we divide by 2. We get 2. And so we begin the loop 4.....2.....1.....4.....2.....1...
Good Luck or Bad Luck?
- Have someone secretly select a three-digit number and enter it twice into her calculator. (For example: 123123) Have her concentrate on the display. You will try to discern her thoughts.
- From across the room (or over the phone), announce that the number is divisible by 11. Have her verify it by dividing by 11.
- Announce that the result is also divisible by 13. Have her verify it.
- Have him divide by his original three-digit number.
- Announce that the final answer is 7.
You can use this to predict Good Luck for him. If you wish to predict Bad Luck, have him divide by 7 in step 3; the final answer will be 13.
Why does this work? Entering a three-digit number twice (123123) is equivalent to multiplying it by 1001. ((123 times 1001 = 123,123)). Since (1001 = 7 times 11 times 13), the six-digit number will be divisible by 7, 11, 13, and the original three-digit number.
The Secret of 73
- For this trick, secretly write 73 on a piece of paper, fold it up, and give to an unsuspecting friend.
- Now have your friend select a four-digit number and enter it twice into a calculator. (For example: 12341234)
- Announce that the number is divisible by 137 and have him verify it on his calculator.
- Next, announce that he can now divide by his original four-digit number. After he has done so, dramatically command him to look at your prediction on the paper. It will match his calculator display: 73
Why does this work? Entering a three-digit number twice (12341234) is equivalent to multiplying it by 10001. ((1234 times 10001 = 12341234)). Since (10001 = 73 times 137), the eight-digit number will be divisible by 73, 137, and the original four-digit number.
The 6174 loop
- Select a four-digit number. (Do not use 1111, 2222, etc.)
- Arrange the digits in increasing order.
- Arrange the digits in decreasing order.
- Subtract the smaller number from the larger number.
- Repeat steps 2, 3, and 4 with the result, and so on. What happens?
Let's try 7173
- Arrange the digits in increasing order. 1377
- Arrange the digits in decreasing order. 7731
- Subtract the smaller number from the larger number. 7731 - 1377 = 6354
- Repeat the process with 6354
- 6543 - 3456 = 3087
- 8730 - 0378 = 8352
- 8532 - 2358 = 6174
- 7641 - 1467 = 6174
- 7641 - 1467 = 6174
- 7641 - 1467 = 6174 (we're in a loop.)
Amazingly, all four-digit numbers (not multiples of 1111) end up in the 6174-loop. No reason has been found for this phenomenon.
The Golden Prediction
This trick takes considerable time, but the effect is spectacular.
Give someone a sheet of paper and a pencil and tell him to do the following
- Number the first 25 lines (1, 2, 3,...).
- Write any two whole numbers on the first two lines.
- Add the two numbers and write the sum on the third line.
- Add the last two numbers and write the sum on the next line.
- Continue this process (add the last two, write the sum) until he has 25 numbers on his list.
- Select any number among the last five on his list, and divide by the previous number (the number above it). Click here to see an example of all this.
Magic Calculator 2 1099
Now for the trick!
Remind him that you do not know his original two numbers or any of the 25 numbers, that you do not know which of the 25 numbers he selected right now, and therefore you cannot possibly know the number on the display.
With great concentration you divine the number presently on his calculator: 'I'm getting a one... then a six...another one.. and an eight...now I'm getting a....zero.. then a three... and... another three... then a nine...'
If your subject selects any number between the last five (#21 through #25) and divides it by the number above it, he'll always get 1.618033989..., which just happens to be the Golden Ratio. (provided, of course, he did all the addition correctly in steps 3-5 above.)
A very special thanks to Bob Kurosaka, retired math professor, for generously sharing these tricks with Curious and Useful Math.
Magic Calculator 2 10 0
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