← Counting Studio← All boards 1/23
A 4-digit PIN uses the digits 0 to 9, and digits may repeat. How many PINs contain at least one 7?
A PIN with a 7≈ 650
Tap a place to fill it.
Your count
Each step you prove lands here, with the tool it used.
A PIN with a 7≈ 650
Each step you prove lands here, with the tool it used.