Im in year 11 and i dont even know how to divide, how embarassing. I know some of the VERY basic stuff like 10 divided by 5= 2. but some questions such as this one:

10 divided by 7, when i do it in my mind it is 1.3 but my calculator gives me 1.4!!!

Could you guys please help me to learn how to divide from the VERY BASICS, ive tried looking at some websites to teach me but they only seem to help me in some questions and leave me clueless in other ones. im not sure this is even a high school topic but i dont know where else to post it. I do fairly well in my other classes such as english but i REALY struggle in maths and always have, i have an exam in around 3 weeks and i cannot afford to fail again...not knowing how to divide prevents me from learning other math topics( i cant think of any at the moment) i rely on my calculator to answer division questions for me but i do get lots of questions which require division in my No Calculator exam paper which basically loses me alot of marks.