MySQL Error: Missing column for constraint in the referenced table

I’m a beginner and just started learning MySQL. I was trying to reference a foreign key to a certain table but i kept getting this error : (Error: Failed to add the foreign key constraint. Missing column ‘CNumber’ for constraint ‘exam_ibfk_1’ in the referenced table ‘course’)

CREATE TABLE Department (
    DCode INT PRIMARY KEY,
    DName VARCHAR(30),
    DContact INT,
    DCollege VARCHAR(30)
);

CREATE TABLE Course (
    CNmuber INT PRIMARY KEY,
    DCode INT,
    CName VARCHAR(30),
    CLevel INT,
    CDescription VARCHAR(200),
    FOREIGN KEY (DCode) REFERENCES Department(DCode)
);

CREATE TABLE Exam (
    ECode INT PRIMARY KEY,
    CNumber INT,
    Letter_Grade VARCHAR(1),
    Number_Grade INT,
    FOREIGN KEY (CNumber) REFERENCES Course(CNumber)
);

And by the way the first foreign key reference works just fine

FOREIGN KEY (DCode) REFERENCES Department(DCode)

I tried looking for answers on google and YouTube but I couldn’t find anything except for solutions that are way too complicated for my dumb brain!

>Solution :

Just read what you wrote carefully.

In the table "Course" you created a column "CNmuber" instead of "CNumber".

Then you tried to reference "Cnumber" that does not exist because the column is called "CNmuber"