A typical user and scene of the software, and a use case diagram.

1. Typical user Lao Chen---Parents of students

Name:	Lao Chen
Gender, Age:	Male, 35 years old
Occupational:	Teachers
Income:	80,000 RMB/year
Knowledge levels and Competencies:	Master, skilled use of computer internet
Living/Working Conditions:	Teaching at the University
Motive, purpose, difficulty:	The teacher is busy, want to use the software to facilitate the practice, counseling learning.
User preferences:	Reading, studying academic materials
User ratio:	50%
Typical scenario:	Go home from work, help your son with math problems
Typical description:	Software engineering is the system

Small Stone---pupils

Name:	Small Stone
Gender, Age:	Male, 6 years old
Occupational:	Pupils
Income:	Not currently
Knowledge levels and Competencies:	In the second grade of primary school, double-digit combined subtraction and 1~9 multiplication can be completed.
Living/Working Conditions:	Learn to work hard
Motive, purpose, difficulty:	To complete homework
User preferences:	Play computer games, play with friends
User ratio:	50%
Typical scenario:	Come home from school, homework.
Typical description:	Knowledge Changes Destiny

Requirements Analysis:

1. There is a chronograph function.

2. You can customize the topic.

3. Determine the correct rate of the answer.

4, prompt operation error.

2. Scenario User story:

　　As a user of the quiz, I want to be able to clearly display the specified time and prompt for the answer so that the homework can be completed quickly.

As a participant in the quiz, I want to be able to conveniently select the operation symbol and enter the topic quickly so that the homework can be successfully completed.

User scenarios:

　Small stone home After school, open the bag to see the teacher decorate homework, content is asked parents out 10 arithmetic problems.

After old Chen learned, open the computer, open the software,

[1] Enter a number in the text box, select the symbol, generate an arithmetic problem.

[2] Small stones enter their own answers within a specified time and click OK.

[3] Lao Chen continued to go out next.

Repeat steps [1][2][3], after 10 operations, click Finish, pop up the statistics correct rate window.

3. Use case diagram

A typical user and scene of the software, and a use case diagram.