**Category:** Measurements, Number Operations, Number Concepts, and Relations & Functions**Suitable for Grade Level:** Secondary and Elementary

**The Math in this Problem:**

In this puzzle, the students work with single digits and are given the task of placing them in different shapes and patterns. Given procedural constraints, such as not permitting certain digit placements, this problem allows the kids to utilize and build on their analytical and problem-solving skills.

Write the numbers 1 through 8 in the circles so that no two numbers inside circles joined by a line differ by 1.

Here is an example of an incorrect solution (because 3 is linked to 4 and 6 is linked to 7):

#### Extensions:

- Which of these digit placing puzzles are possible using the digits 1 through 9?

- Make your own digit placing puzzle using the digits 0 through 9, but don’t allow the 0 and 9 to be side by side.
**Two Player Game:**Players take turns placing the digits. The first player who cannot place loses.