Mathematical modeling turns an open-ended real-world problem into assumptions, a model, a solution, and a defended recommendation, and its answers matter only if they are both close to a credible reference and physically feasible; existing benchmarks either score solver fragments or grade reports with an LLM judge, leaving those numbers unchecked. We introduce TB-MathModel (the Terminal-style Mathematical Modeling Bench), the first benchmark to make complete contest-style modeling problems agentic, verifiable, and terminal at once, over 18 real CUMCM and MCM problems (2023--2025). Each task ships the verbatim statement, official attachments, and figures in a containerized terminal; the agent returns one JSON artifact, scored on the numeric core of the final question against a reproduction of the Outstanding-award paper. Two design choices distinguish it: direction-aware, one-sided scoring, which never penalises beating the anchor, and two-layer feasibility verification---a programmatic gate over six decidable invariant forms plus 624 Lean~4 obligations---with a hard gate that zeroes infeasible answers. Each task is scored against a panel of human outstanding papers rather than one, so a model must be close to many accepted answers; across seven multimodal entries (three seeds each) the strongest reach a multi-reference O-Eval of 64.58%, while the $2.54 open model holds 59.81% at 1/100 the cost. TB-MathModel turns the numeric core of modeling into a reproducible, machine-checkable signal for measuring long-horizon modeling competence and for collecting agent trajectories. The source code is available at https://github.com/wxj630/terminal-bench-math-modeling.
Figures & tables
Benchmark
#Tasks
#Fig.
Evaluation signal
Agentic
Physical
Lean
Multimodal
Mamo Huang et al. (2025b)
1209
–
Solver check
✗
✗
✗
✗
ModelingBench Qian et al. (2025)
68
–
LLM judge
✗
✗
✗
✗
MM-Bench Liu et al. (2025)
111
–
LLM judge
✗
✗
✗
✗
TB-MathModel (ours)
18
21
Executable verifier
✓
✓
✓
✓
Table 1: The closest mathematical-modeling benchmarks. Only TB-MathModel combines a complete contest problem, an agentic terminal run, an executable verifier, physical-feasibility checking, and a machine-checkable proof, on a multimodal task (“Judge”: LLM grades a report; “Solver”: solver checks one formal artifact).
Figure 1: Why modeling is hard to evaluate, and what TB-MathModel changes. (a) In the status quo an LLM judge grades a report on organisation while the numbers are never checked. (b) TB-MathModel runs the problem, attachments, and figures in a terminal container, requires one structured artifact, scores it one-sidedly against an O-award reproduction, and verifies feasibility with a gate and Lean certificates—so a plausible-but-infeasible answer is caught.
Figure 2: The TB-MathModel construction and evaluation pipeline. Build : official statements, attachments, and PDF figures are compiled into a task directory. Run : the agent works inside a network-isolated terminal container and writes one JSON artifact. Evaluate : the artifact is scored by a direction-aware, one-sided panel against an O-award reproduction, and independently checked by a programmatic feasibility gate plus a Lean 4 certificate layer; a failed gate zeroes the task.
Model + harness
Art.
O-Eval (%)
Multi-BO
Cost (USD)
GPT-6 Astra + codex
18
64.58±2.93
1.132±0.02
246.41
Fable 5.1 + claude-code
18
63.11±1.33
1.081±0.05
272.80
DeepSeek-Flash + opencode
18
59.81±1.25
1.000
2.54
GPT-5.5 xhigh + codex
18
59.75±1.55
0.998±0.01
99.37
Kimi K3 + opencode
18
58.23±1.12
0.953±0.04
23.26
GLM-5.3 + opencode
18
57.78±1.30
0.941±0.05
28.15
Table 2: Main results: the seven multimodal entries, 18 tasks, sorted by O-Eval . “Art.”: tasks with a scoreable artifact; cost: USD per 18-task pass. O-Eval is the multi-reference panel score (%) and Multi-BO the same score relative to the DeepSeek V4.1 Flash baseline ( 1.000 = level with Flash), both three-seed means ( ± std).
Figure 3: Left: multi-reference O-Eval versus cost (log scale)—the Pareto frontier is compressed, with near-frontier scores at two orders of magnitude lower cost. Centre: O-Eval per entry. Right: O-Eval by suite, showing the CUMCM–MCM gap.
Harness
O-Eval (%)
Multi-BO
opencode
59.81±1.25
1.000
claude-code
59.83±1.13
1.081±0.05
codex
59.84±1.21
1.085±0.03
DeepSeek (native)
59.88±1.20
1.092±0.03
Table 3: Harness sensitivity, holding the model fixed (DeepSeek-Flash, 18 tasks, three seeds). Multi-BO is 1.000 for the opencode reference harness by definition.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Slug
Contest
Topic
Final Q
cumcm-2023-a-heliostat
CUMCM 2023 A
Heliostat field design
Q3
cumcm-2023-b-multibeam
CUMCM 2023 B
Multibeam survey lines
Q4
cumcm-2023-c-vegetable
CUMCM 2023 C
Vegetable pricing and replenishment
Q4
cumcm-2024-a-dragon
CUMCM 2024 A
Bench-dragon kinematics
Q5
cumcm-2024-b-production
CUMCM 2024 B
Production decision
Q4
cumcm-2024-c-crop
CUMCM 2024 C
Crop-planting strategy
Q1
Appendix
Table 4: The 18 TB-MathModel tasks and their O-award anchors. “Final Q” is the contest question whose numeric core is scored; oracle coverage is 18/18.
Slug
Final Q
Source
#Fig.
#Metric
cumcm-2023-a-heliostat
Q3
CUMCM 2023 A
2
5
cumcm-2023-b-multibeam
Q4
CUMCM 2023 B
8
4
cumcm-2023-c-vegetable
Q4
CUMCM 2023 C
0
2
cumcm-2024-a-dragon
Q5
CUMCM 2024 A
5
2
cumcm-2024-b-production
Q4
CUMCM 2024 B
1
6
cumcm-2024-c-crop
Q1
CUMCM 2024 C
0
2
Appendix
Table 5: Per-task summary. “Final Q” is the sanctioned final question.
Task
GPT-6 Astra
Fable 5.1
GPT-5.5 xhigh
DeepSeek-Flash
cumcm-2023-a-heliostat
86.2
80.7
80.5
80.2
cumcm-2023-b-multibeam
94.0
80.5
91.7
59.3
cumcm-2023-c-vegetable
64.3
64.3
64.3
64.3
cumcm-2024-a-dragon
83.4
83.4
83.4
83.4
cumcm-2024-b-production
95.7
80.5
87.2
87.2
cumcm-2024-c-crop
88.2
83.5
99.7
63.8
Appendix
Table 6: Per-task multi-reference O-Eval (%) for four representative entries. Each column’s mean equals that entry’s main-table O-Eval , so the per-task values reconcile with the board.
Figure 4: An official statement figure, cropped from the CUMCM 2023 A PDF and delivered inline in the prompt. 21 such figures across 6 tasks are load-bearing: the final answer depends on reading them.
Model
Harness / tier
Art.
O-Eval (%)
Multi-BO
GPT-6 Astra
codex CLI / max
18
64.58±2.93
1.132±0.02
Fable 5.1
claude-code CLI / max
18
63.11±1.33
1.081±0.05
GPT-5.5 xhigh
codex CLI / xhigh
18
59.75±1.55
0.998±0.01
DeepSeek-Flash
opencode CLI / high
18
59.81±1.25
1.000
Kimi K3
opencode CLI / high
18
58.23±1.12
0.953±0.04
GLM-5.3
opencode CLI / high
18
57.78±1.30
0.941±0.05
Appendix
Table 7: Multimodal board, 18 tasks, sorted by O-Eval . “Art.” is the number of tasks with a scoreable artifact; O-Eval is the multi-reference panel score and Multi-BO the same score relative to the DeepSeek V4.1 Flash baseline, both three-seed means ( ± std).
Slug
Paper id
Slug
Paper id
cumcm-2023-a-heliostat
A175
mcm-2023-a-plant
2309229
cumcm-2023-b-multibeam
B226
mcm-2023-b-maasai
2315379
cumcm-2023-c-vegetable
C050
mcm-2023-c-wordle
2307946
cumcm-2024-a-dragon
A016
mcm-2024-a-lamprey
2407093
cumcm-2024-b-production
B159
mcm-2024-b-submersible
2419984
cumcm-2024-c-crop
C038
mcm-2024-c-tennis
2401298
Appendix
Table 8: Outstanding-award anchor per task.
Quantity
Oracle (anchor)
GPT-5.5
DeepSeek V4.1
max_head_speed_mps
1.246266
1.24626636
1.24626636
max_speed_ratio
1.604793
1.60479338
1.60479338
Appendix
Table 9: Dragon-dance (CUMCM 2024 A, Q5). All three roles agree; the paper value is the outlier and is infeasible.
Quantity (yuan, 7-year)
Anchor (exact MILP)
GPT-5.5
DeepSeek V4.1
waste-surplus profit
40,418,877
40,320,587
41,559,515
50%-discount profit
58,718,967
66,485,662
70,378,276
Appendix
Table 10: Crop-planting (CUMCM 2024 C, Q1). Special case: the anchor is a reproducible exact optimum under the paper’s per-plot cap.
Quantity
Anchor
GPT-5.5
DeepSeek V4.1
Fable 5.1
daily cap
11,000
20,000
16,000
14,000
visitor fee (USD)
55
20
30
30
annual visitors (M)
1.492
1.453
1.434
1.728
resident acceptance
1.000
0.743
0.938
0.696
sustainability score
1.007
0.900
0.706
79.1
total revenue ($M)
431.6
369.6
366.7
458.5
Appendix
Table 11: Juneau tourism (MCM 2025 B, final question). The sustainability score is reported on different unit scales by different agents.
Form
Example obligation
domain / range
probability ∈[0,1] ; thickness >0
integer / binary
decision bits ∈{0,1} ; counts integer
ordering
q95≥ mean; peak ≥ average
exact identity
area = count × w × h; union ≤∑
finite domain
decision-bit count ∈{16,17}
partition / sum
land-use counts sum to the grid
Appendix
Table 12: The six decidable invariant forms covering the hard-error branches of all 18 tasks.
Level
Content
Layer
A — unit / range
probability ∈[0,1] , thickness >0
gate + Lean
B — consistency
area = count × w × h; partitions sum
gate + Lean
C — physical truth
does this field really produce 60 MW?
neither
Appendix
Table 13: Three levels of feasibility. Both layers cover A and B; C needs formalised physics.
Task
Oblig.
Skipped
Task
Oblig.
cumcm-2023-a-heliostat
12
0
mcm-2023-a-plant
66
cumcm-2023-b-multibeam
3
1
mcm-2023-b-maasai
17
cumcm-2023-c-vegetable
7
0
mcm-2023-c-wordle
3
cumcm-2024-a-dragon
3
0
mcm-2024-a-lamprey
302
cumcm-2024-b-production
61
0
mcm-2024-b-submersible
8
cumcm-2024-c-crop
5
0
mcm-2024-c-tennis
7
Appendix
Table 14: Obligations per task (624 total across 18 tasks). “Skipped” obligations were reported as missing evidence rather than silently satisfied.