Although everyone thinks mathematics is universal language, this is not always the case. During the years of teaching international groups I have noticed several ways for notations etc. What is obvious for me, may not be obvious for you and vice versa. Something is used here in Finland, something in French-speaking countries. [br][br]Here are some examples: [br][br][list][*][color=#0000ff]decimal numbers:[/color][math] \quad 1,2 \;\text{(like in Finland)},\, 1.2\; \text{(in many countries)} [/math][br][/*][br][*][color=#0000ff]multiplication: [/color] [math] \quad 2\times 3=2\cdot 3\; [/math][br][/*][br][*][color=#0000ff]dividing: [/color] [math] \quad 2\div 3=2/3=2:3=\frac 2 3[/math][br][/*][/list][br]The point is that we have to find a common language to understand each other. Because you are studying in Finland, you have to also understand the other teachers, mainly from Finland, and THEY HAVE TO UNDERSTAND YOU. This means you should use Finnish notations; not always ones you have used in your home countries.[br][br]