Complete the Sequence: Finding Missing Numbers in 12 10 8 7 6 5 4 3 2 1

Question

12 ☐ 10 ☐ 8 7 6 5 4 3 2 1

Which numbers are missing from the sequence so that the sequence has a term-to-term rule?

00:13 Let's fill in the missing pieces together.

00:16 First, notice the difference between each item. We call this difference, D.

00:28 Now, complete it according to the pattern we discovered.

00:38 Let's continue with the same pattern by adding 1.

00:45 And there you have it! That's how we solve this problem.

It is possible to see that there is a difference of one number between each number.

That is, 1 is added to each number and it will be the next number:

$1+1=2$

$2+1=3$

$3+1=4$

Etcetera. Therefore, the next numbers missing in the sequence will be: $8+1=9$

$10+1=11$

11 , 9