Open Middle®
Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to make a true pattern where the pattern increases by the smallest amount possible.
Hint
How can we tell whether the digits we place in the boxes actually make a pattern? How can we tell if the pattern increases each time by the digit we choose? How can we tell what would be a bad digit to choose for how much it increases by?
Answer
The pattern that increases by the smallest amount possible is 9, 16, 23 which increases by 7.
Source: Robert Kaplinsky
Suggested by my student, Nicole: 8, 14, 20
Ooops! We did not read that the digit, 0, was not permitted.
Zero would have been helpful! 🙂
6, 09, 12 … 3