Set Up Your Texas Instruments BA II Plus Calculator for Maximum Efficiency

Keith Tan, CFA CFA Level 1 7 Comments

The CFA Level 1 exam is gruelling, not just for the amount of material you have to understand, but also the speed at which you need to solve the questions.

For each session, you are given 180 minutes to answer 120 questions. That is an average of one and a half minutes for each question. The calculator is the only productivity tool that you have for the exam, so it pays to set it up for maximum efficiency.

For this tutorial, we are going to learn some 2 simple settings for the BA II Plus calculator that can help you shave precious seconds off each calculation.

Number of Decimal Places

The first step is to make sure the number of decimal places gives sufficient precision. You can check the number of decimal places your calculator outputs by keying [2nd] [Format].

The default output precision is 2 decimal places. This is insufficient. Key in [9], followed by [Enter] to change the output precision to up to 9 decimal places. Now, you may be thinking, you don’t need 9 decimal places. When you set this to 9, the calculator will output the appropriate number of decimal places, up to a maximum of 9 decimal places. For example, when you key in 50 divided by 8, your calculator will display 2 decimal places, but when you key in 22 divided by 7, your calculator will show 9 decimal places.

Order of Operations

The second step is to set the order of operations. Now go into the format settings again, by pressing [2nd] [Format]. Press the down arrow key 4 times, and you will arrive at the order of operations. The default mode of the calculator is ‘Chn’, which actually means chain operation. This means that the calculator will compute in the order that you key in.

For instance, if you want to find the present value of $1000, 4 years from now, with a discount rate of 7%, you will need to key in 1000/1.07^4.

Under the default chain operation mode, you need to compute the denominator first, because you do not know the value of it. There are a few ways you can do this. The shortest way is to key in [1.07] [xy] [4], which gives you a denominator of 1.3107. Press the [1/x] key to get the reciprocal, [x] by [1000], press [=], and we get the correct answer.

AOS Mode

Now, there is an alternative mode that is more intuitive and will save you some keystrokes. This is known as the AOS mode. AOS stands for Algebraic Operating System, and what it does is, it intelligently prioritises the operations based on mathematical rules. So if you key in [1000] [/] [1.07] [xy] [4], the calculator automatically knows that the power operation has to take precedence over the divide operation. This mode not only reduces the number of keystrokes, it is also more straightforward to use.

To change to the AOS mode, simply key in [2nd] [Set] if you are still at the order of operations settings. You will see the word ‘AOS’ appear on your calculator.

In summary, the 2 simple settings to help shave precious seconds off your calculations. Set the number of decimal places to 9, and the order of operations to AOS mode.

Congratulations! Your calculator is now optimised for maximum efficiency for the CFA exam!

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