Step {{ step < 5 ? step : 4 }}/4

Unpacking Sigma

👆 Tap to reveal terms

{{ s1.A * i }}
?
+

Writing Notation

🖐 Drag to build

{{ term }} +
∑

Linearity Property

↔️ Slide to split

Combined Split

Sum Formula (Gauss)

🔗 Tap pairs that sum to 11

Matched pairs will appear here
{{ pair[0] }} + {{ pair[1] }} = 11
5 pairs × 11 = 55
🎉

Master of Sigma!

You've successfully unpacked, built, split, and calculated series like a pro.