Love For MathCreative Math Education

DIY Challenge 3: Five numbers, one pattern

Try this for 5 different numbers and share your findings. Do you notice anything interesting? Why do you think is it happening?

Note: Please use a calculator if you feel the need.

What students worked out15

  • Student 1

    I think the pattern here is that if you choose a number do the following steps the every time you divide you move down by a place value e.g I start with a 4 digit the after I divide I end up with a 3 digit then 2 digit

  • Student 1

    Also that the 3 digit number that you think of then make it a 6 digit number then do the division it ends up with the same 3 digit number that you started with e.g 454 is my 3 digit no. I make it 454454 then 454454/7=64922 then 64922/11=5902 then 5902/13=454

    • Karanteacher

      Why do you think this is happening?

      • Student 1

        Because all the numbers that you divide are prime numbers

        • Student 1

          For this problem

  • Student 2

    WE WILL ALWAYS END UP WITH THE SAME NUMBER THAT WE STARTED WITH. IF I (for eg:) started with 274 the end number will also be 274 as
    step 1 274
    step 2 274274
    step 3 [(274274*7)*11]*13 or 274274*1001
    I have done the same trick before i have a math magic book
    another thing
    if the number is
    2 DIGIT-101
    3 DIGIT-1001
    4 DIGIT-10001
    5 DIGIT-100001
    6 DIGIT-1000001

    • Karanteacher

      Interesting. Looks like there’s a small error in step 3. What do you think?

  • Student 11

    Can’t find the reason, but I think that Rehan is right

  • Student 14

    You end with the number you started with.

    • Student 14

      Same as 77/11.

  • Student 3

    6 digit no formed is 1001 times that of 3 digit no
    and 7,11,13 are prime factors of 1001
    so final answer comes same

  • Student 15

    sir the number gets divided so many times that it results in the number that we thought of like sir I took 555 and at the end the result was 555

  • Student 15

    and sir i think its doing that because the number is divisible by 11 and there are other prime numbers dividing it to

    • Student 15

      no sir

  • Student 9

    If we multiply a 6 digit number by 7*11*13 or 1001 the answer would be the same number.