mathbase Open & Invitational
A two–stage competition series designed for serious students who love problem-solving: a fast-paced multiple-choice Open round, followed by a proof-based Invitational with cash prizes.
Please fill this out if you intend on competing in the MathBase Open.
Format overview
- MBO — 40 competition-style multiple choice questions · 60 minutes · algebra, geometry, number theory, probability.
- Top 8 scores qualify for MBI (MathBase Invitational), a proof-based round with a cash prize pool.
- MBI — 4 proof-based questions · 90 minutes · deep number theory and algebra.
- Top 3 students in MBI receive money from the prize pool.
February 2026 schedule
The February MBO/MBI will be held on 2/24/2026 (February 24) (Eastern Time Zone).
- • MBO: 1:00 PM – 2:00 PM (strictly)
- • MBI qualifiers announced: 4:00 PM
- • MBI: 5:00 PM – 6:30 PM
- • Winners announced: 7:30 PM
Cash rewards will be forwarded in the week following the competition.
MBO · MathBase Open
Monthly competition math round
• 40 multiple choice questions
• 60 minute time limit
• Topics: algebra, geometry, number theory, probability
• Questions are designed to feel like a mix of AMC/AIME-style problems and original MathBase problems.
• Scoring details and proctoring instructions are included with each contest set.
Advancement to MBI (MathBase Invitational)
The top 8 scores in each edition of MBO receive an invitation to MBI, the proof-based round with a cash prize pool.
MBI · MathBase Invitational
Proof-based invitational round
• 4 problems, each requiring full written proofs
• 90 minute time limit
• Focus areas: number theory and algebra
• Problems reward depth of reasoning, creativity, and clear exposition.
February 2026 MBI prize pool
prize pool
February MathBase Invitational champion
1st place: $500
2nd place: $200
3rd place: $50
Cash rewards for the February MBI (1st: $500, 2nd: $200, 3rd: $50) will be forwarded in the week following the competition.
Invitations are sent by email to top MBO performers with full instructions and submission guidelines.
Ready to compete?
Sign up for the next MathBase Open (MBO) using the form below. It is free to compete, and prize money is awarded to the top three in the MathBase Invitational.