《数学课程标准》指出:估算在日常生活与数学学习中都有着十分广泛的应用,培养学生的估算意识,发展学生的估算能力,具有重要的价值。纵观现行教材,估算教学已经成为数学计算的重要组成部分,是计算策略的一种,更是人们在日常生活中运用相当广泛的数学运用方式和行为。同时估算越来越多的应用到人们的日常生活中,因为,在现时生活中人们经常运用到估算。例如,买一件物品大概需要多少钱,一件物品大约有多重,有多长。因此,要想提高学生的估算能力,必须从低年级开始打好基础,适应实际生活的需 The Mathematics Curriculum Standard states that estimation plays a very important role in daily life and mathematics learning. It is of great value to train students ’estimation awareness and develop students’ estimation ability. Throughout the teaching materials, estimation teaching has become an important part of mathematical calculation, is a calculation method, but also in the daily life of people to use a wide range of mathematical methods and behavior. At the same time more and more estimates are applied to people’s daily life, because people often use estimation in current life. For example, how much it costs to buy an item, how often an item is multiplied, and how long. Therefore, in order to improve students’ ability to estimate, we must start from the lower grades to lay a solid foundation to adapt to the needs of real life