At first glance this seems simple, but many people miscount. The key is to go step by step.
- 1 large outer circle
- 4 medium circles inside it → total 5
- Each medium circle has 2 small circles → 4 × 2 = 8
Now add everything: 1 + 4 + 8 = 13 circles
Final check:
- 1 big
- 4 medium
- 8 small
Total = 13