1. Let the students know the time unit seconds, and know that 1 minute = 60 seconds.

2. Make students initially establish the concept of 1 min 1 sec.

Preparation of teaching AIDS and learning tools: theme map courseware (or wall chart), various clocks and watches, clock face model, oral calculation card.

Teaching process:

First, create situations and introduce new lessons.

Teacher: (The courseware shows the theme map, in which the clock time is 1 1: 59) This is the scene of the Spring Festival Evening. Look at the big clock on the wall. Can you tell us what time it is? The new year's bell is about to ring. Let's count down.

Teachers and students count down together: 15, 14, 13, …, 1.

Teacher: To measure such a short time, we need to use a smaller unit-seconds. (writing on the blackboard: seconds) Say, where do you still use time units and seconds?

Students can give examples: rocket launch, running competition, etc.

Second, independent exploration, learning 1 min = 60 seconds.

1. Explore the tools for measuring "seconds".

Teacher: How to measure such a small unit as "second"? This is a watch shop (courseware is given away). Which watches do you think can measure seconds? Tell your ideas to the students in the group.

Organize group discussion, and students give their opinions widely. The following findings may be found:

(1) electronic watch (or clock).

(2) a clock with a second hand.

(3) stopwatch.

2. Learning 1 min = 60 seconds.

Teacher: Electronic clocks, stopwatches and clocks with second hands can all measure time in seconds. Now please dial the clock face in your hand. What did you find? (If the students have difficulties, the teacher will prompt: How much is the minute hand? 1? The second hand goes 1 lap, and how much does the minute hand go? )

Student activities and teacher inspection.

On the basis of feedback, the teacher summed up the running relationship between the second hand and the minute hand, that is, the second hand went 1 lap for 60 seconds, and the minute hand just went 1 grid, from which 1 minute = 60 seconds.

3. Complete the exercise 15, question 1, and let the students fill in the appropriate time units.

3. How long is the experience of 1 minute?

1. Establish the concept of 1 minute.

Teacher: How long is 1 minute? Let's take a closer look.

The teacher turned on the power of the clock face and asked the students to watch the second hand on the clock face walk quietly.

Teacher: 1 min What can we do? Now I'll give you 1 minute, and ask the students in groups 1, 2 and 3 to do whatever they want, and the students in group 4 can do whatever they want.

Feedback.

The teacher stressed: Although 1 minute is short, you can do a lot of things by making good use of it.

2. Complete the exercise with practice 14, question 10.

Teacher: How long does it take you to run 50 meters? Please talk in the group, and the group leader will record each student's grades. Compare, who runs fastest?

3. Understand the history of clocks and watches.

Teacher: Without these clocks, how can we know when the time passes at 1 min 1 sec?

On the basis of students' full expression of opinions, the teacher plays courseware and shows some ancient timing tools.

Teacher: Interested students should look for more information and hold a press conference next time.

Fourth, class summary.

After summing up, ask the students to complete the exercise 14, question 6.

Feedback.

Teacher: What's your estimate? Check it when you get home, or ask mom and dad to help you record the time.