This document summarizes a study that analyzed the mathematics performance of grade five students in Thailand using the Newman Procedure. The study aimed to identify the levels at which students make errors in problem solving and compare performance between high- and low-achieving students as well as between students in Bangkok and a poorer performing province. Most students struggled at the comprehension and transformation levels. Poor performers made more errors in comprehension, while good performers performed well across levels. Students in the poorer province struggled more with comprehension, while those in Bangkok struggled with transformation.