Defense of Information Technology "Binary and Number System Conversion" in Senior High School

1. If binary contains decimal, such as 11.01B, how should it be converted to decimal?

[Reference answer]

The method of summation by weight expansion is adopted. The weight of each digit in the integer part is 21 and 20 from high to low, and the weight of each digit in the decimal part is 2-1 and 2-2 from high to low. Therefore, (11.01) 2=1 × 21+1 × 20+0 × 2-1+1 × 2-2=(3.25) 10

2. What method should be used to convert decimal 10.25 to binary?

[Reference answer]

For the integer part, you can use the reverse remainder method of dividing by 2. Use 10/2 to record the quotient 5 and the remainder 0, then use 5/2 to record the quotient 2 and the remainder 1, then use 2/2 to record the quotient 1 and the remainder 0, and finally use 1/2 to record the quotient 0 and the remainder 1, so the remainder is arranged in reverse order to get 1010B.

For the decimal part, you can use the method of multiplying by 2 to get an integer. Use 0.25 × 2 to record the product 0.5 and the integer 0, and then use 0.5 × 2 to record the product 1 and the integer 1. Therefore, the integer is arranged in positive order to get 0.01B.

Therefore, 10.25D=1010.01B.

3. How is the computer converted into binary when processing sound?

[Reference answer]

Sound is an important way for people to express and transmit information. When using computers to process sound, it is necessary to convert the analog signal of sound waves into digital signals, that is, the digitalization of sound. The method of sound digitization is to collect the amplitude of sound waves at a certain time interval and convert it into a binary number sequence, that is, through sampling, quantization and coding.

Sampling is to measure the analog value of the sound analog signal at an equal time interval and extract it discretely. The quantity value obtained from sampling shall be quantized by stages, that is, the sampling value shall be transformed to the nearest digital value, that is, the original continuously changing value shall be approximately represented by a limited number of values. Through sampling and quantization, a continuous waveform is converted into data represented by a series of binary numbers to form binary code.

4. How do you make students understand the mutual conversion of binary, octal, decimal and hexadecimal in this lesson?

[Reference answer]

This class involves a lot of calculations, so when I teach, I first teach the conversion between binary and decimal, and fully understand the conversion method through group discussion, independent inquiry and other ways; Then I learned the carry rules and representation methods of octal and hexadecimal, as well as the relationship between octal, hexadecimal and binary; At last, we summarize that the conversion between decimal and binary is extended to the conversion between decimal and R-ary. Through gradual learning, students can understand and master knowledge.

5. At the end of the course, you did not ask students to do exercises directly, but practiced with the numerical conversion of color code. What is the purpose of doing this?

[Reference answer]

After the new lesson is taught, it is necessary to set up some exercises to check the students' mastery of knowledge.

If you use the method of doing exercises directly to show students a question of decimal conversion, you may not be able to arouse students' interest. However, with the numerical conversion of color codes, students will be interested in exploring unfamiliar knowledge, and analyze that this conversion is actually a conversion between hexadecimal and decimal. At the same time, students can also exercise their ability to analyze and solve problems through this form of exercise.

6. When explaining the decimal conversion, you used the method of discussion, but you found that after discussion, a student still could not calculate. What will you do about it?

[Reference answer]

In the classroom, teachers play the role of guides, and should give full play to the dominant position of students. Therefore, discussion can cultivate students' ability to think independently, cooperate and communicate, and reflect the requirements of the new curriculum reform. However, if the discussion fails to achieve the desired effect, it will inevitably affect the progress of the course and students' interest in learning the course. Therefore, I will give guidance in time to solve this problem.

First of all, I will ask the student what he did not understand, and give timely guidance to the students for their problems. In the process of explaining the follow-up knowledge, I will continue to pay attention to the student's learning status, so that students can keep up with the progress of the course and ensure the learning effect.

Secondly, after the end of the course, I will find this student to communicate separately, encourage students to actively participate in group activities, and if there are problems in the process of discussion, ask the group members and teachers for advice in time, so as not to delay learning. In addition, I will also ask the students whether there are other reasons for not learning knowledge, and carry out targeted solutions.

Finally, I will actively reflect on my teaching methods, review whether I have any omissions in organizing student activities, and whether I have paid attention to students' learning status. In addition, I will listen to some excellent courses to learn more teaching experience.

Through continuous improvement of teaching methods and teaching contents, we can achieve the level of high-quality courses, so that students can learn not only knowledge but also learning methods in the course.