Current location - Training Enrollment Network - Mathematics courses - Participate in math primary school
Participate in math primary school
Xiao Ming got it right 15.

The answer process is as follows:

(1) Let Xiao Ming answer question X correctly.

(2) According to the math contest ***20 questions, the question that can be answered wrong or wrong is 20-X.

(3) According to the correct answer to a question, score 5 points, if the answer is wrong or not, deduct 3 points, and Xiao Ming scores 60 points, that is, 5x-3(20-x)=60.

(4) Simplification: 8x= 120, solution: x= 120/8= 15.

Extended data:

Law of integer division

(1) Start with the high order of the dividend, first look at how many digits there are in the dividend, and then try to divide the dividend by the first few digits. If it is smaller than the divisor, divide it by one digit as much as possible;

(2) Write the quotient on ex-dividend;

(3) The remainder after each division operation must be less than the divisor.

Solutions to such problems:

(1) Carefully examine the question, find out the meaning of the question, find out the unknown quantity, and set it as the unknown quantity.

(2) Find out the equivalence relation in the problem and list the equations.

(3) Solve the equation correctly.

(4) inspection.