







Formula when i know the GST total 
20171031 

Duncan pose la question : HI  I've added up the GST from a pile of receipts and would like to know what the total cost of goods would be without GST. I don't want to add up 100's of receipts again with the cost before GST but I do need this total cost.
i.e.) I know I paid $400 GST, what would the formula be to find out the cost of what I purchased before taxes? Your help is much appreciated! Penny Nom lui répond. 





formula when i know the GST total 
20171031 

Duncan pose la question : HI  I've added up the GST from a pile of receipts and would like to know what the total cost of goods would be without GST. I don't want to add up 100's of receipts again with the cost before GST but I do need this total cost.
i.e.) I know I paid $400 GST, what would the formula be to find out the cost of what I purchased before taxes? Your help is much appreciated! Penny Nom lui répond. 





Why does 10x10x10 give 1,000.0000000000001? 
20170412 

Randolph pose la question : Hi, On your calculator I found that a box 10 by 10 by 10 inches has a volume of 1,000.0000000000001 cubic inches. Can you explain the numeral 1 thirteen places past the decimal? Thanks, Randy Penny Nom lui répond. 





2,0061234...484950 
20160924 

Mimi pose la question : Compute the following:
2,0061234…484950 Penny Nom lui répond. 





600(1+0.05)^7 
20160421 

chelsey pose la question : I am unsure on how to solve this problem, 600(1+0.05) 7 ? Penny Nom lui répond. 





I was paid 67% of the total owed 
20160125 

Julie pose la question : I was paid $27000. This is 67% of the Total Owed. The Total Owed is unknown. How do I calculate the amount of the Total Owed? Penny Nom lui répond. 





777777 times 111111 
20100707 

Chew pose la question : What is 777777 times 111111 without using a calculator? Chris Fisher lui répond. 





Figure out the square root of something 
20091220 

eric pose la question : is there an ez equation to figure out the square root of something? Harley Weston lui répond. 





Acreage calculation 
20091029 

Angela pose la question : I am appraising a small portion of property for a right of way for a new sewer line. I have appraised many similar
projects in the past; however the engineer always calculated the exact acreage and/or dimensions of the parcel
being taken. My survey states the following: "141 linear ft. of 25' permanent R/W. I divided the linear feet x 12 and mult. by 25
to get the square footage, but it just doesn't seem right. Any suggestions? Am I missing something? Robert Dawson lui répond. 





(570 divided by 15) multiplied by (5 plus 26) 
20090624 

Sherrie pose la question : What is the answer to this math question:
(570 divided by 15) multiplied by (5 plus 26)..........
Thank you,
Sherrie:) Penny Nom lui répond. 





36cm to the second power divide 10cm 
20090226 

val pose la question : 36cm to the second power divide 10cn Penny Nom lui répond. 





How accurate is the following calculation? 
20080903 

Craig pose la question : Given that these numbers are only accurate to 2 decimal places, how accurate is the following calculation?
1.73  2.16 + 0.08 + 1.00  2.23  0.97 + 3.02 = 0.47
How do I work out the accuracy? Penny Nom lui répond. 





A one pass calculation of standard deviation 
20070319 

Murtaza pose la question : Hi
I searched the listings but couldn't find what i am looking for. I have a dataset and i am allowed only 1 pass through it. At the end of this pass i must have the mean and standard deviation. Calculating the mean is easy as also demonstrated in your listings. I think the same can be done for standard deviation as well. But the doubt that i have is this : Will the calculated standard deviation be sequence dependent ? i.e. if i change the order in which the data items enter the system, will the std deviation also change ??
Thanks in advance
Murtaza Penny Nom lui répond. 





Calculations 
20021215 

Mahdi pose la question : This problem is rather general, but it usually makes a lot of problems. I almost have no difficulty in math and physics questions, but unfortunately I'm not at all accurate in simple one or two digit calculation. I even sometimes make silly mistakes in simple sums like 7+4=12 or 4+5=11! Is there any effective way to reduce these mistakes? Walter Whiteley lui répond. 





A calculation with 6 numbers 
20010616 

Edwin pose la question : I'm asked to come with, and program (in Ansi C) an algorithm that calculates all the possible results of a calculation with 6 numbers and one result. For example: I want all calculations with the numbers 3, 3, 8, 8, 2, 9, and with a result of 786. all numbers may be used once, arithmetical operations allowed are +  / *, fractions are not allowed. The problem here is what is a fast method to do this (i.e. what's algorithm that can to this). Claude Tardif lui répond. 





Human Calculator 
19980914 

Pam Sloan pose la question : I recently saw a special on NBC Dateline about a man known as the human calculator. They called him Mr. Math. I want to know more about his books, seminars, and activities. Also, what is his real name? Patrick Maidorn lui répond. 

