How long is this table? It is the second lesson of the second unit "Observation and Measurement" in the second volume of Grade One Mathematics published by Beijing Normal University. Teachers guide students to participate in actual measurement activities, and initially realize the necessity of unifying measurement units and the actual length of "cm". There are three activities in the textbook: one is the estimation activity, which allows students to estimate the length of the surrounding objects. The second is to talk, discuss and communicate, and realize the necessity of unifying measuring tools. The third is measurement, and learn to actually measure with tools such as rulers.

Analysis of learning situation

Organize students to communicate, gesture and operate for many times, truly understand the practical significance of 1 cm, organize students to observe, communicate and measure for many times, and learn to make simple measurements correctly.

Teaching objectives

1, through the process of measuring the length of the same object with different tools, we can understand the diversity of measurement methods in real life and initially realize the necessity of unifying length units.

2. Know the centimeter, know its practical significance, and learn to estimate the length of smaller objects.

3, will use the scale to measure the length of the object.

4. Feel the fun of mathematics in the learning process, cultivate the sense of cooperation, exercise the ability of observation, operation, spatial imagination and reasoning, and stimulate the interest in learning mathematics.

Teaching emphases and difficulties

Key points: Understand the meaning of "1 cm", initially cultivate the awareness of estimation, and learn to make simple measurements correctly.

Difficulties: correctly understand the practical meaning of "1 cm" and make simple measurement correctly.