IB考试：A-level 数学考试技巧.

　　������������������ A-level Math Exam Technique

　　Examiners use certain words in their instructions to let you know what they are expecting in your answer. Make sure that you know what they mean so that you can give the right response.

　　Write down, state - You can write your answer without having to show how it was obtained. There is nothing to prevent you doing some working if it helps you, but if you are doing a lot then you might have missed the point. Calculate, find, determine, show, solve - Make sure that you show enough working to justify the final answer or conclusion. Marks will be available for showing a correct method. Deduce, hence - This means that you are expected to use the given result to establish something new. You must show all of the steps in your working. Draw - This is used to tell you to plot an accurate graph using graph paper. Take note of any instructions about the scale that must be used. You may need to read values from your graph. Sketch - If the instruction is to sketch a graph then you don&apos&apost need to plot the points but you will be expected to show its general shape and its relationship with the axes. Indicate the positions of any turning points and take particular care with any asymptotes. Find the exact value - This instruction is usually given when the final answer involves an irrational value such as a logarithm or a surd. You will need to demonstrate that you can manipulate these quantities so don&apos&apost just key everything into your calculator or you will lose marks. If a question requires the final answer to be given to a specific level of accuracy then make sure that you do this or you might needlessly lose marks.

　　Some Do&apos&aposs and Don&apos&aposts

　　Dos

　　Do read the question Make sure that you are clear about what you are expected to do. Look for some structure in the question that may help you take the right approach. Read the question again after you have answered it as a quick check that your answer is in the expected form. Do use diagrams In some questions, particularly in mechanics, a clearly labelled diagram is essential. Use a diagram whenever it may help you understand or represent the problem that you are trying to solve. Do take care with notation Write clearly and use the notation accurately. Use brackets when they are required. Even if your final answer is wrong, you may earn some marks for a correct expression in your working. Do avoid silly answers Check that your final answer is sensible within the context of the question. Do make good use of time Choose the order in which you answer the questions carully. Do the ones that are easiest for you first. Set yourself a time limit for a question depending on the number of marks available. Be prepared to leave a difficult part of a question and return to it later if there is time. Towards the end of the exam make sure that you pick up all of the easy marks in any questions that you haven&apos&apost got time to answer fully.

　　Don’ts

　　Don&apos&apost work with rounded values There may be several stages in a solution that produce numerical values. Rounding errors from earlier stages may distort your final answer. One way to avoid this is to make use of your calculator memories to store values that you will need again. Don&apos&apost cross out work that may be partly correct It&apos&aposs tempting to cross out something that hasn&apos&apost worked out as it should. Avoid this unless you have time to replace it with something better. Don&apos&apost write out the question This wastes time. The marks are for your solution!