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 [u]they have to understand you[/u]. This means you should use Finnish notations; not always ones you have used in your home countries.[br][br]