How large can you make it (2)? (Inspired by Satyen Nabar)

Logic Level 3

Shift exactly 2 matchsticks to another position so as to convert the number 5008 into the largest four digit positive integer.

Details and Assumptions:

Form a regular number by moving just 2 matchsticks.
Use of exponents / mathematical signs / tricks is not allowed.
Rotating / turning the figure is not allowed.
All digits look like this: (for clarifying the shape of digits)

Inspired by this problem .

The answer is 9909.

2 solutions

Nihar Mahajan
Jun 18, 2015

Shift the left bottom match of the last $8$ to complete the first $9$ . Then just shift the left bottom match of the first $0$ in the middle of it to get it $9$ as well. Thus largest possible 4 digit number is $9909$ .

Moderator note:

Applying the same rules, can you find the smallest four digit positive integer instead?

heh, i get 9805 too. But what about the number 15 003? you put two stick before the first number? :D

Jan Novotný - 5 years, 12 months ago

Instead of 15003, you can get something even bigger!!.. remove the top and bottom sticks of the first zero and insert a 1 right there and you get 511108, which is a lot bigger...

Aditya R Mohan - 5 years, 11 months ago

That's what I came up with too.

Ryan Berg - 5 years, 7 months ago

The rules stated 4 digits.

Nikki Juetten - 5 years, 10 months ago

98118 will be the biggest one

Kailas Andhale - 5 years, 7 months ago

ah... I made it 9805 ..but then I hit the reveal solution button... I was really close.. >:(

Rishabh Tripathi - 5 years, 12 months ago

Challenge master : The smallest number is surely 0000 and smallest positive number is 0006 and the smallest 4 digit : 2008

Abhijeet Verma - 5 years, 9 months ago

Since Rotating / turning the figure is not allowed, how can you make 2nd digit to 9 in this way? Isn't it a rotating of matchstick? It should be 9900.

Zakir Dakua - 5 years, 7 months ago

In response to Challenge Master: Is the smallest number $2008$ ?

Nihar Mahajan - 5 years, 12 months ago

I also got the smallest number as 2008

Rehman Hasan Tyeb - 5 years, 12 months ago

I think it's 0006

Nikki Juetten - 5 years, 10 months ago

I got the smallest number as 2008 as well ;)

Mehul Arora - 5 years, 12 months ago

I thought they said no turning or rotating ?

Quang Nguyen - 5 years, 8 months ago

Didn't read the sentence that said "Rotating / turning the figure is not allowed." :( But just for the record, if rotation was indeed allowed, the largest number you could do is 9985

Eduardo Neo - 5 years, 8 months ago

I missed it because I don't look at 9s as having that bottom part I just looked at it as if it were a reflective P

Frederick Sparks - 5 years, 8 months ago

You breaked your own rules. In the 2nd digit you rotated the vertical stick horizontally to make it 9 the answer must be 9900

Lahkadhirsinh Gohil - 5 years, 5 months ago

I got 98118. By removing the top and bottom from a zero, i was able to add a digit position.

Monte McGuire - 5 years, 3 months ago

I got 98118. By removing the top and bottom from a zero, i was able to add a digit position.

Monte McGuire - 5 years, 3 months ago

91,188 remove top and bottom of first zero leaving 51,108. Convert the 5 to a 9 and 0 to an 8. Fully fits within the guidelines.

Jonathan Rust - 4 years, 11 months ago

For some reason I thought I couldn't turn the matches.

Erin Pilon - 4 years, 11 months ago

I got largest no 511109 Remove up and down of 0 and place them just beside.

Nivedit Jain - 4 years, 3 months ago

Chris White
Sep 30, 2015

Got on first try, last time this problem showed up there was no 4 digit limit making for some really big numbers. the 4 digit limit makes you want to make as many 9s as possible, during the last digit to a 9 gives you an extra match stick to move to the first digit to make it a 9, and you can just move a match stick on the second digit to make it a 9 making 9909 the answer.

How large can you make it (2)? (Inspired by Satyen Nabar)

Inspired by this problem .

The answer is 9909.

2 solutions

Moderator note:

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