Open Middle®
Directions: Using the digits 1 to 9, at most one time each, place a digit in each box to make 5 composite numbers.
Hint
What kinds of numbers are often composite?
What single digit numbers are composite?
What single digit numbers are composite?
Answer
There are 1230 possible answers. Here are three examples:
1: 4, 12, 35, 69, 78
2: 4, 12, 35, 69, 87
3: 4, 12, 35, 76, 98
1: 4, 12, 35, 69, 78
2: 4, 12, 35, 69, 87
3: 4, 12, 35, 76, 98
Source: Owen Kaplinsky
Your answers are composite…Aren’t you looking for prime? I am going to put this up with one set of answers to see if my 6th graders see the errors…and to see if they can come up with all prime.
Oops. That was a typo. This is the composite number problem but I copied and pasted and forgot to change that word. Here’s the prime number version: https://www.openmiddle.com/prime-numbers/
Is it ok if I select 144
9, 12, 34, 56, 78
Is that the real answers?
Is that the real answers?
I solved by filling in the last digit of the two digit numbers with 2, 4, 6 & 8 and then filled in my odd numbers for 9, 18, 36, 54, 72.
9,78,63,54,21
6,12,48,39, and 75
9,12,34,56,78
9,78,63,54,21 And I cannot type in this site
9,78,63,54,21
6, 72, 54, 10, 93
You really should put a warning on this one. Printing it takes a lot of paper when you don’t realize how many answers there are.
Thanks for the feedback, we’ve limited it to 3 answers.
4,18,32,56,70
9,12,34,56,78
9,7863,54,21
oops
that was wrong
i mean 9,78,63,54,21