“…Recent studies reveal that specialists such as scientists, engineers, or mathematicians employ estimation before actually using assessment tools to reach to exact results (Jones & Taylor, 2009;Jones et al, 2012). Educators who emphasize the importance of estimation skills (Brade, 2003;Desli & Lioliou;Reys, 1984;Reys & Bestgen, 1981;Reys et al, 1991;Sowder & Wheeler, 1989;Van den Heuvel-Panhuizen, 2001) note that it is a skill required not only for a few occupations and daily life, but also helps develop numerous mathematical skills, such as mental activities, spatial visualization, assessments, and understanding quantities (Kose, 2013). That is why it is imperative and necessary to instill skills such as reasoning, interpreting, mental calculus, creative thinking, and estimation in the students, from their earliest years on.…”