Skip to main content
STREAK
0d
LV 1
0 XP
Institute site
Problem Bank
· arith-2
Arithmetic & Number Sense · Summation
MathCounts style
●○○○○ 2/10
~2 min
⏱ 0:00
Compute
1
+
2
+
3
+
⋯
+
40
1 + 2 + 3 + \cdots + 40
1
+
2
+
3
+
⋯
+
40
.
gauss-sum
pairing
Submit
Hint 1 of 3
Show solution
∂
Learn
▤
Courses
Σ
Problems
⊕
Contests
↻
Review
∇
Dashboard
λ
AI Coach