







Adding two negatives 
20180204 

From Pinasshakoane: (23)+(3) Answered by Penny Nom. 





Multiplication and repeated addition 
20161123 

From Anandmay: Hello
I was looking closely at early arithmetic where I found how we discovered properties of Arithmetic.
Like:2 x 3 = 3 x 2.
This can be proved by considering a 2D figure(actually,quadrilateral) having length consisting of 2 boxes of
1by1 dimensions and breadth of 3 boxes of the same dimensions.
Now,consider it again,but,this time,length of 3,and breadth of 2 of such 1 by 1 boxes.
We now notice that we can fit the 2 types of rectangles formed on each other precisely.
So the multiplicative property of commutativity is true for all natural numbers as we can generalize the result(in our mind,for self satisfaction).
Now,can you find me a nice satisfactory reason of why a fraction times a natural number equals the number times the fraction?
I mean, for example,i can understand the meaning of 3 x 2/3 to be three times 23rd,that is, 2/3+2/3+2/3.Fair enough.
But here is the problem:By definition and actual meaning of multiplication, a x b means the repeated sum of b,done 'a' times.
So what is the meaning of doing 2/3 x 3?The repeated addition of 3 how many times??2/3 times??Not making sense,right?And even
we have not proved yet the commutative property of numbers INCLUDING fractions.So how can we resolve this problem and make these things meaningful?
Thanks Answered by Penny Nom. 





Complex numbers in standard form 
20160115 

From Michael: express the following complex numbers in standard form (2+3i)+(52i) Answered by Penny Nom. 





Multiplication and order 
20110121 

From Janet: IN A MULTIPLICATION SENTENCE BASED ON A DRAWING..IS THERE ANY ORDER FOR THE MULTIPLICAND ANG MULTIPLIER FOR THE ANSWER TO RIGHT? Answered by Robert Dawson. 





Convert to multiplication 
20101023 

From angelina: how to covert 5+5+5=15 to multiplication Answered by Penny Nom. 





4.5 PLUS 29 
20100907 

From kiona: 4.5 PLUS 29 Answered by Penny Nom. 





Adding in base six 
20090329 

From Lucy: If you are working in base 6,
what do you have to add to 4(base 6) to get 10(base 6)???? Answered by Penny Nom. 





Adding fractions 
20080917 

From amanpreet: please can you help me to simplify:
2(c3) / 7 + 3(4c2)/2 Answered by Penny Nom. 





.9 repeating plus .2 repeating 
20080610 

From megan: How do you express the addition of .9 repeating plus .2 repeating? Answered by Penny Nom. 





Adding rational functions 
20080429 

From Jonathon: 1/(x+3) + 1/(x^2+5x+6) = Answered by Penny Nom. 





Base 5 arithmetic 
20080306 

From Jana: Hello, my name is Jana, i have asked a question here previously about how to count in base5. I am happy now because i can convert any number now and it is very easy for me. The only thing i am having trouble with is understanding how to do a maths sum or times base5 numbers. it is just a bit hard for me. So do you think you could explain how to do a sum in base5 and how to do a multiplication sum. Please help...Thankyou Jana!! Answered by Harley Weston. 





Adding fractions 
20071231 

From Lisa: As an educator in Adult Education, I am preparing a young man for a US Government test. The equation I have trouble with is explaining the following equation. It asks: If it takes A 3 days to dig a certain ditch, whereas b can dig it in 6 days, and C in 12, how long would it take all three to do the job? I know the equation is 1/3 + 1/6 + 1/12 and it equals = 7/12 but I don't understand how it equals 7/12. This simple math eludes me. So the question is not the final answer of 1 and 5/7 of days but where one comes up with the 7/12? Answered by Penny Nom and Claude Tardif. 





Linear systems 
20060921 

From Alexander: Hello, i have a math assignment due tonight at midnight and i need some help please
It is using the addition method to solve linear systems Answered by Penny. 





1/x + 1/y 
20060811 

From Sonya: what is 1/x+1/y = ? is it equal to 1/x+y or what? Answered by Penny Nom. 





Adding polynomials and counting the terms 
20060428 

From Kris: Suppose that two polynomials, each containing 3 terms, are added. Is it possible for the sum to contain more than 3 terms? fewer than 3 terms? exactly 3 terms? Explain. Answered by Leeanne Boehm and Steve La Rocque. 





Adding 10 and multiples of tens to one and two digit numbers 
20051213 

From Meghan: I am teaching in a grade 2/3 class and I am struggling with trying to find a simple way of explaining to the students how to add 10 and multiples of tens to one and two digit numbers. Answered by Diane Hanson. 





Adding fractions 
20031116 

From Ken: My name is Ken and I am taking my GED course for my High School and have not been in a class for 35 years. I am doing this for retraining. I am at the part about fractions. Here is an example that I am having trouble with.
1 3/7 + 4 2/3 + 11/21
They have no common denominators. Could you PLEASE help me. If you could send me a step by step explanation it would be greatly appreciated. Answered by Penny Nom. 





Common Denominator 
20020826 

From Slobodanka: What is a Common Denominator? Answered by Penny Nom. 





Adding algebraic fractions 
20020320 

From Dolores: I get totally confused with this problem. I get confused with the getting the lowest terms. 4/x5 + 2/x 10/x^25x Answered by Penny Nom. 





F = 3 + 3 
20020319 

From Jessica: F= 3 + 3 WHAT IS F????? Answered by Penny Nom. 





Adding algebraic fractions 
20020123 

From Francine:
Hello, I've come up with an answer for the following problem but it's not the same as the book's answer. However, the book has a lot of mistakes in it and I don't know if I'm doing it properly or not. Your help would be soooo appreciated. It's driving me crazy.The problem is:
2 + 3 + 4
 +  + 
(x1)^3 (x1)^2 (x1)
[(x1)^3 is (x1) to power of 3 etc.] Answered by Penny Nom. 





Adding vectors 
20020112 

From Lena: how do you add vectors together? If you are given the length and angles of both vectors and are asked to add/subtract them, how do you do it? I know you are supposed to do the head to tail method, but whenever i try it i get the wrong answer. I need help setting it up. example: A is 2.7cm, and 60 degrees, B is 1.6cm and 135 degrees, find the magnitude and amplitude Answered by Penny Nom. 





Odd plus even is odd 
20011014 

From James: Why is the sum of an odd number and an even number always odd? Answered by Peny Nom. 





Adding functions 
20010219 

From Jackie: f(x) = x^{2} + 1; g(x) = x^{2}  1 find a) ((f+g) of h)) (x) b) ((fg) of h)) (x) c) ((f of h)  (g of h)) (x) Answered by Penny Nom. 





What is wrong with these probelms? 
20010209 

From Cindy: Hi, I am a planning on becomming a teacher and i am asked to find out what is wrong with these probelms and how i would go about showing a student what is wrong with them!! Error in patterns: 13/35=1/5; 27/73=2/3; 16/64=1/4 4/5+2/3=6/8; 2/5+3/4=5/9; 7/8+1/3=8/11 2/3*3=6/9; 1/4*6=6/24; 4/5*2=8/10 Answered by Leeanne Boehm and Penny Nom. 





Order of operations 
20001126 

From Margaret Pratt: My daughter has a math question and I am afraid I am of no help. Can you help? 2x5/2+15= She arrives at 8 as the answer and has been told this is incorrect. Any help you can give would be appreciated. Answered by Penny Nom. 





Word addition 
20000705 

From Harman Chaudhry: What is the value of DISHES if SEE + THE + WAITER + WASHES = DISHES. In addition, I know there is a name for these types of problemswhat are they actually called? Answered by Chris Fisher. 





Why does division start from the left? 
20000524 

From Salil Dave: Addition, subtraction and multiplications start with right most digit and proceed left, but division starts from leftmost digits and goes right ... why? Answered by Harley Weston. 





Adding fractions 
20000423 

From A grade 6 student: In adding fractions, how do I rewrite the fractions so that the denominators are equal? The problem is 3/4 + 1/6 = The other problem is 11/18 + 4/9 = Answered by Penny Nom. 





Addition 
20000111 

From Deanna: what is the answer for 20+5+323+98 Answered by Penny Nom. 





A number between 
19981125 

From Jimmy Nikola: A number is less than 3,425 + 8,630 and greater than 7,614 + 4,429. What could the number be? This question is on page 93, question number 23. in Silver Burdett Ginn Math book, which is a 3rd grade math book. Answered by Jack LeSage. 





Adding Fractions 
19981015 

From Lindsay: please help me!!!! Answered by Harley Weston. 





A Sum or Product of Fractions 
19981006 

From Emily Robb: Find a pair of fractions that when they are multiplyed and added the sum /product is the same Answered by Penny Nom. 





calcul des hh,mn,sec 
20080119 

From gillot: bonjour, mon fils à des additions et soustractions d'horaire et je n'arrive pas à trouver
la règle pour lui espliquer comment il faut faire
il y a t il une formule pour les additions et soustractions
merci par avance pour vos réponses Answered by Claude Tardif. 





A=B+C+D+F+G+H+J 
20071127 

From Boubendir: voila ma question et comme savoir les nombres additioné en etulisant le resultat
A=B+C+D+F+G+H+J
au debut ons a les B,C,D,F,G,H,J on connaissent leur valeur comment retrouver
valeur on etulisant leur resultat Answered by Claude Tardif. 

