







Un angle solide 
19980506 

From Giol: Qu'est ce qu'un angle solide ?? J'ai beau chercher dans mes documents, je ne trouve rien de bien convaincant sur le sujet si ce n'est une définition qui me semble bien vague et creuse ... En vous remerciant de votre attention ( puissiez vous illustrer votre réponse par un exemple, s.v.p...) Bonjour,
Answered by Chris Fisher. 





Area Calculation 
19980505 

From Jessica: There's a question I have that I hope you can answer about calculating area. It seems to me that common sense says that if you have say 100 meters of fence, the area you can enclose should be a constant. Yet the math says it is not so. For example if you build a rectangle 10x40 the enclosed area is 400 square meters. But if you build a rectangle 5x45 then the area is 225 square meters, even though you've started with the same amount of fencing. I know this is true, but can anyone explain IN ENGLISH why this is so? Answered by Harley Weston. 





Pyramid 
19980504 

From Lisa Nathan: How do you find the area of a pyramid? Answered by Harley Weston. 





Mathematical Arrays 
19980501 

From Gene Lanctot: Could someone please explain what a mathematical or arithmetical array is? The array in question is used in grade three math in Ontario. I would also like to know what its purpose is. Answered by Harley Weston. 





Multiplying by Nine  Chismbop Style 
19980427 

From Noria Jones: About a year ago a grade 5 teacher at my son's school taught the children how to multiply the 9 times table on their fingers quickly. It was part of a kind of finger math kind of thing... Answered by Patrick Maidorn. 





Logic and Matrix Instruction 
19980424 

From Robin Booker: I need assistance with instruction strategies to teach the construction of a matrix, solving a logic problem. Providing instruction in the construction of a simple matrix , no problem. However, I stumpted on this one. Five players were chosen as All Stars at the basketball banquet. Based on the following clues, find the player's name, team, uniform color and number of points scored.... Answered by Harley Weston. 





Mean and Standard Deviation 
19980422 

From Kit: i have a problem of maths. i think the level of the question is secondary. question: Find the mean and the standard deviation of the numbers:1, 3, 4, 5, 7. i hope u solve this question. thank you so much! Answered by Harley Weston. 





Using your fingers 
19980421 

From Ian Sutherland: My 7yearold son, in Grade 2, constantly uses his fingers to count. I know for now this is a useful crutch but at what point should he stop? Answered by Diane Hanson. 





Hour Hand Movement 
19980419 

From Chris and Angela Bradley: My wife and I are haveing an argument over the answer to this question, what is the total number of degrees through which the hour hand of the clock moves in 3 hours and 18 minutes? Thanks in advance. Answered by Chris Fisher. 





A Car Wash 
19980404 

From Lisa GotimerStrolla: Al washes a car in six hours. Fred washes a car in eight hours. How long will it take them to wash a car together? Answered by Harley Weston. 





Seed Problem 
19980326 

From Jody A. Johnson: Seed Problem: The height of an amazing plant grown from a seed varies linearly with the time it has been in the ground. After six days it is 6cm tall and after 60 days it is 15.8m (1580 cm) tall.  Write the particular equation giving the height as a function of time.
 Find the intercepts and explain them.
 What would be the height in one year?
 How long would it take for the plant to grow to a height of 1km?
I'm having a problem with this equation. Could you please help. Thank you. Answered by Penny Nom. 





The day of the week, July 24, 1837 
19980321 

From Colleen K.: What day of the week (Mon. Tues. Wed. etc...) was July 24th, 1837? Answered by Chris Fisher. 





Curvature of the Earth 
19980316 

From Robert Dyck: How can I find the curvature per mile of the earths surface? What is it? Answered by Harley Weston. 





The Largest Factor 
19980315 

From Senthuran Nadarajah: When each expression is evaluated for different values of n, the answers will differ. For each expression, find largest natural number that will divide the result for all natural number values of n. n^5  5n^3 + 4n Answered by Harley Weston. 





Matrices 
19980310 

From Ksya:
 A and B are matrices. If A^n=B^n, can we say A=B or det(A)=det(B) or det(A)^n=det(B)^n ? Any conditions ???
 If B^(1) is the inverse of B, where B is a matrices. Can we say [(B^(1))^n][B^n]=I, where I is identity matrices? Any conditions???
Answered by Doug Farenick. 

