Optimizing Inference Cost for Arabic–English Mathematical Reasoning in LLMs

Sahar Melhem, Ahmad M Mustafa


Abstract
Large language models (LLMs) can solve mathematical problems through prompting, yet not all reasoning is cost-justified when using paid APIs. We study prompt-only methods for overthinking control in the black-box setting across four datasets: Arabic GSM8K, English GSM8K, English SVAMP, and ArMATH, each evaluated on 100-question subsets divided into Easy, Medium, and Hard categories. We test Direct Answer, Chain-of-Thought (CoT), First Answer Anchoring (FAA-lite), Confidence-Triggered Escalation (CTE), Self-Consistency, Verification, Arabic prompt variations, and Language-Optimal Prompt Routing (LOPR). CTE achieves 90% accuracy on Arabic GSM8K at 1.14 calls/query, 96% on English GSM8K at 1.06 calls/query, and 98% on SVAMP at 1.08 calls/query. Self-Consistency leads on ArMATH at 90% but costs 2.00 calls/query. Verification consistently increases token cost without accuracy gains. Format-Controlled CoT is the best single-call Arabic method; Bilingual-Glossary CoT is consistently harmful. CTE calibration reveals that explicit low-confidence outputs are rare (<1%), so CTE succeeds mainly because high-confidence predictions are accurate, not through active uncertainty detection.
Anthology ID:
2026.arabicnlp-main.13
Volume:
Proceedings of The Fourth Arabic Natural Language Processing Conference
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Muhammad Abdul-Mageed, Tamer Elsayed, Houda Bouamor, Samhaa El-Beltagy, Hend Al-Khalifa, Ahmed Abdelali, AbdelRahim Elmadany, Abdellah El Mekki, Kareem Darwish, Sakhar Alkhereyf, Hamzah Luqman, Salam Khalifa, Samar Magdy, Zaid Alyafeai, Injy Hamed, Wajdi Zaghouani, Imed Zitouni
Venue:
ArabicNLP
SIG:
SIGARAB
Publisher:
Association for Computational Linguistics
Note:
Pages:
170–178
Language:
URL:
https://aclanthology.org/2026.arabicnlp-main.13/
DOI:
Bibkey:
Cite (ACL):
Sahar Melhem and Ahmad M Mustafa. 2026. Optimizing Inference Cost for Arabic–English Mathematical Reasoning in LLMs. In Proceedings of The Fourth Arabic Natural Language Processing Conference, pages 170–178, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Optimizing Inference Cost for Arabic–English Mathematical Reasoning in LLMs (Melhem & Mustafa, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-main.13.pdf