6.0305 9.8739 8.5673 7.6 125 3.9965

Reserved integer

Keep one decimal place

Keep two decimal places

Keep three decimal places

Second, the approximate value of quotient

1. Read the scene map on page 39 carefully and answer the questions.

What questions can I ask?

Can you list the formulas? (using a calculator)

Talk about your results with the students in the group. What did you find?

Write it at the back:

2. Try to find the approximate value of quotient by rounding.

Tips: When the quotient cannot be divided, in general, the approximate value of the quotient should be obtained by "rounding method".

Keep two decimal places, one decimal place or one integer place by rounding, and the result should be

Third, cyclic decimals

The height of the Three Gorges Dam is about several times that of the Ming Tombs Energy Storage Dam.

I can work out the formula:

What do you find through vertical calculation?

Then the quotient of this problem can be expressed as: 185÷75=

2. Calculate 8.05÷3.7=

3. Can you tell me what circular decimal, finite decimal and infinite decimal are?

4. Have you learned everything? Let's test it!

1. Find the approximate value of the quotient by "rounding" and fill in the table below.

Keep an integer, a decimal place and two decimal places.

23÷7

46.4÷ 13

5 1.5÷29

2. Are the following figures cyclic decimals? And explain why.

1.535353…… 2.037999…… 0.3333……

2. 1374642893…… 5.696969

3. Judge the size and explain the reasons.