Below is a long division with some digits hidden. Which of the following digits could represent one of the empty boxes?
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This particular long division layout is used in multiple countries including South Korea, Japan, and the United States.
Most countries follow a similar pattern (the most common difference is having the quotient be written to the right rather than above the problem), but there are a few major variations; two samples shown below.
73/18=4 remainder 1, 18x4=72, 7 is a correct answer also.
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The divisor has only one digit, so it cannot be equal to 18.
In Portugal we don't use that way to solve
I have never seen this kind of notation for a division. I don't think it's used in Germany and Austria?
I'm portuguese and I don't use that way.
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Care to elaborate? Do you have a different way to write out your long division?
I meant that in my country (Portugal), we actually use what is described above as Argentina's way.
excuse me ? i haven't seen this problem before , i mean this "long division" , so i don't understand how this division worked . could you please give me an explanation ? thank you !
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Long division written this way is a bizarre way American kids are taught to do division, or used to be. I didn't run into it myself until I was an adult, and for solving this problem I had to look it up on Google to figure which number goes there, as it it definitely counter-intuitive. I think the problem should carry an explanation of the system, since people around the world cannot be expected to know it.
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I agree. Maths should be universal language. I had the same problem. But was too lazy (and angry I guess) to get through google to find information.
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@Ivan Constantineau – Really? I'm pretty sure everyone learned what long divisions before the age of 10.
Regardless, how do you think I could clarify what "long division" is?
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@Pi Han Goh – I learned a long division as a small child. I learned it using a totally different notation, however.
53/13=4 with remainder of 1 also works! So 5 is also a correct answer.
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True, but 13 does not fit into a single square provided, as it has two digits, so it cannot be an answer. In other words you can't fill the entire long division outline correctly using this option.
The number (we'll call y) must be such that y × 4 + 1 = number ending with 3 in the ones place. The possible numbers that work are 3 and 8. The number given is 8, thus, the only number on the list that works is 8.
8 × 4 + 1 = 33
A systematic algebraic approach: Let k be the divisor, m be the 10's place digit of the dividend, and n the 10's place digit of the number below the dividend. k , m , and n are all digits in { 1 , 2 , … , 9 } . Then from the structure of the division problem:
( 1 ) 1 0 m + 3 − ( 1 0 n + 2 ) = 1 ⇒ 1 0 m − 1 0 n = 0 ⇒ m = n
( 2 ) 1 0 m + 3 = 4 k + 1 ⇒ 5 m + 1 = 2 k ⇒ m must be odd and k = 2 1 ( 5 m + 1 ) for m odd.
So, trying m ∈ { 1 , 3 , 5 , 7 , 9 } gives only two possible single-digit ( m , k ) solutions: ( 1 , 3 ) and ( 3 , 8 ) . Only 8 is a solution option.
Only thing we have to focus is that 4 and 2
We have to find a sure number that is in the options and can fill any of the boxes, so the only thing we can calculate is a multiple of 4 whose one's digit 2
Only possibilities : 4 x 3 = 12
4 x 8 = 32
Only 8 is available in options, hence answer is 8
It is possible to solve this problem knowing only the two and the four. By following the long division procedure, we know that 4 times a single digit number must give a double digit number with two as its last digit. The second single-digit factor must be one of the options provided, so we have either: 4 x 5= 20, 4 x 6= 24, 4 x 7= 28, and 4 x 8= 32. Since 8 is the only factor that gives a product ending with 2, it must be the answer.
The first omitted digit, the divisor, has to be larger than the omitted number of the dividend, since the quotient is one digit. Also, since there is only a remainder of 1, the second two omitted numbers have to equal each other. There is only one number on the list which meets these requirements - 8, since 33 ÷ 8= 4, with a remainder of 1.
The two digit multiples of 4 with two ones are 12 and 32. You cannot go past 32 because then the divisor will not be a single digit anymore. Since 3 and 4 do not appear as choices, the answer must be 33/8.
it should be,
4x+1=..3
or, 4x+1=33.............[without 3, no numbers work here]
or. 4x= 32
or,x=8
Let be n the divisor the division, n × 4 it must finish in 2 . ∴ 8 × 4 = 3 2 finish in 2
good attempt, but your solution is incomplete. 3x4 = 12 <<< it finish in "2" as well.
Of the answer choices, only one of them (8) offers a product of 4 with 2 as its first digit.
Yes, 8 is the right answer. Can you show us why this is indeed the correct answer?
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There are two possibilities.
1 3 ÷ 3 = 4 with remainder 1 or 3 3 ÷ 8 = 4 with remainder 1.
Only the second version contains a number on the list, namely 8