Mathematics deals with data analysis, integration of various fields of knowledge, involves proofs, deductive and inductive reasoning, and generalizations. Mathematical education aims to provide the ability to mathematize the thought process of children i.e., the use of mathematical knowledge in everyday life using various strategies. Algorithm is a step-by-step procedure made to achieve a certain objective in a finite time. The most used are addition, subtraction, division, and multiplication, which were used in elementary grade. Key Points In the above-mentioned situation, an informal algorithm strategy was used by the student and it reflects student's mathematical thinking process. An informal algorithm is a strategy in which problems are solved using basic rules and processes used in daily life which have no historical significance. The problem can be solved using basic techniques which we use in our daily life. It helps in developing the mathematical and logical thinking of an individual. Through this process, math is done in the mind quickly and efficiently and also helps in doing math instantly without the effort put into operations and processes. Using these strategies will help the teacher to know the children's process of understanding concepts.​ Hence, from the above points, it can be concluded that in the above-mentioned situation, an informal algorithm strategy was used by the student and it reflects student's mathematical thinking process.