Is 5X10 'five times ten' or 'ten times five'?

Englishmypassion

Senior Member
India - Hindi
Hello all,
Namaste!
There are four twos: 2, 2, 2, 2. To teach multiplication to little children, should they be written 4x2 ,or 2x 4?
Does the expression 5x10 mean 'five times ten' , or 'ten times five' ? Which number is being multiplied and which number is multiplier (the number of times) and the multiplication symbol x is used, as in 5x10?
Thanks a lot.
 
  • Cagey

    post mod (English Only / Latin)
    English - US
    I would write this 2, 2, 2, 2 as 4X2.

    In same way, I refer to this :idea::idea::idea: as "3 light bulbs". I give the number of occurrences first and then name what I am counting.

    Similarly, I read 5X10 as "five times ten", reading across in the order of the numbers.
    I think of it as 10+10+10+10+10.

    Added: If you said "ten times five" I would think of it as:
    5+5+5+5+5+5+5+5+5+5 and write it as 10X5.
     
    Last edited:

    Englishmypassion

    Senior Member
    India - Hindi
    One more question:
    If the equation is written vertically, in the following way, then which number shows the number of occurrences and which number is the multiplicand or is being multiplied?
    25
    x10
    Thanks.
     

    natkretep

    Moderato con anima (English Only)
    English (Singapore/UK), basic Chinese
    In our primary school maths books, 4 x 2 is explained as four lots of two. This is in agreement with what Cagey has said.

    I'd see

    25
    x 10

    as another way of writing 25 x 10, hence 25 lots of 10.
     

    natkretep

    Moderato con anima (English Only)
    English (Singapore/UK), basic Chinese
    Actually, now that I've done more searching, I'm seeing that too. Like here:
     

    natkretep

    Moderato con anima (English Only)
    English (Singapore/UK), basic Chinese
    I don't think it is a BrE-AmE distinction. I think people haven't been bothered to standardise things because the result is the same, as Keith said. Just use one method and stick to it.
     

    DonnyB

    Sixties Mod
    English UK Southern Standard English
    If, as I did, you had to learn your "times tables" at Junior School, you would remember that:

    "five tens are fifty" (from the ten times table)
    "ten fives are fifty" (from the five times table)

    Simples! :D
     

    Englishmypassion

    Senior Member
    India - Hindi
    If, as I did, you had to learn your "times tables" at Junior School, you would remember that:

    "five tens are fifty" (from the ten times table)
    "ten fives are fifty" (from the five times table)
    Simples! :D

    Thanks a lot. I really need to learn multiplication/times tables as my calculation is really week. I will learn them that way.:)
     

    Glenfarclas

    Senior Member
    English (American)
    Isn't that odd; all my life I've seen this the other way round!
    So have I, which is why I would tend to write lists with the multipliers on the right, like:

    widgets × 2
    eggs × 48
    keychains × 19,​

    etc.

    Oh, I am really in a fix now.
    No you're not. Multiplication is transitive, so a × b = b × a. You ask "which number is being multiplied," but the truth is that they are both being multiplied.

    As to your question about how to pronounce "5 ×10", no English speaker would ever read that as "ten times five." Always from left to right.
     

    Englishmypassion

    Senior Member
    India - Hindi
    Thank you, everybody.
    So we write and read the multiplication table of 10 as follows:
    1x10= 10 (One ten is ten.)
    2x10=20 (Two tens are twenty.)
    3x10=30 (Three tens are thirty.)
    4x10=40 (Four tens are forty.)
    5x10=50 (Five tens are fifty.)
    6x10=60 (Six tens are sixty.)...
    Am I right ?
     

    DonnyB

    Sixties Mod
    English UK Southern Standard English
    Yep! The full set goes up to 12 and there are 12 in each table... 12 x 12 = 144.

    Similar to these :)

    We'll make a mathematician out of you yet! :D
     

    Englishmypassion

    Senior Member
    India - Hindi
    Yep! The full set goes up to 12 and there are 12 in each table... 12 x 12 = 144.

    Similar to these :)
    Wer'll make a mathematician out of you yet! :D
    Thank you VERY much. I have seen 12 in each table for the first time and find myself lucky :) to have been spared 2 in each set, though I had to learn, and Indian students still learn, tables of 1 to 20. So I got a good concession. :)
    I really start feeling dizzy the moment I open a maths book.:confused::(
     

    Parla

    Member Emeritus
    English - US
    If you want to teach little kids basic multiplication as a shorthand way of adding multiple sets, I guess that's okay (we weren't taught that way). But at some point, they must learn that mathematically, 5 x 10 is precisely equal to 10 x 5.
     

    neal41

    Senior Member
    USA, English
    Multiplication is transitive, so a × b = b × a. You ask "which number is being multiplied," but the truth is that they are both being multiplied.

    As to your question about how to pronounce "5 ×10", no English speaker would ever read that as "ten times five." Always from left to right.
    The correct term is 'commutative'. Multiplication is commutative. That means that a x b = b x a for all a and b. 'a x b' is pronounced 'a times b' and 'b x a' is pronounced 'b times a'. '5.3 x 2.6' is 'five point two times two point six', which of course equals 'two point six times five point two'.

    Addition is also commutative. a + b = b + a for all a and b. 5 + 2 = 2 + 5.

    Addition and multiplication are also associative. That means that (a + b) + c = a + (b + c) for all a, b, and c, and that (a x b) x c = a x (b x c) for all a, b, and c.

    Multiplication of integers can be viewed as repeated additions. 5 x 2 = 2 + 2 + 2 + 2 + 2 = 5 + 5. Multiplication of rational numbers and real numbers cannot be so interpreted.
     
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