How Many Will There Be? Xs and Os

Objective

Students will use the patterns they find in the first four steps to predict the 50th step.

Inspired by the website Visual Patterns.

Steps

1. Students look for patterns and predict how many Xs will be at step 10.
2. I reveal the solution (it's 31) and ask students to predict step 50.
3. After showing my solution (there are 151 Xs) I challenge students with a new formation of Xs and Os. (The secret: in this version, you start with 4 Xs and add 12 Xs at each step.)

Resources

• Worksheet (PDF)
• Worksheet (Google Slides)