We propose an intelligent accessible mathematics approach, called i-Math for people with visual impairment on reading math expressions in Thai. Math expressions in various forms were investigated for developing a set of rules to correctly read the math expressions. Our proposed approach has revealed it is possible to construct a practically automatic math expressions reading system by suitable technologies of speech processing. The i-Math system prototype was tested to generate the accurate speech (intelligibility and overall speech quality) for a math problem sample set and its usage (user satisfaction) was determined by voluntary participants, both students and teachers. The intelligibility indicated that i-Math can generate the understandable pronunciations for math text. Overall speech quality showed that the utterances read by i-Math are good quality and understandable with slight effort. The user satisfaction questionnaire can be included that the teachers and students had positive perceptions toward the use of i-Math.