If you are in Line Mode with a Line input, you can switch to MultiLine Font which enables you to show a series of calculations on a scrolling screen. If you choose the small font, you can fit even more lines on the screen at one time. Great for a series of fast calculations.

We know that we can press S=D to change an exact result to a decimal answer, but on the Classwiz there are two ways that can give you a decimal approximation. There is the approximately equal to feature and you can change the setting so that you get a decimal result every time.

You can input a recurring decimal on a Casio Classwiz, despite there not being a dedicated button to do so. This is particuarly useful if you need to convert a recurring decimal to a fraction using your calculator.

Input a recurring decimal such as 0.3 recurring by inputting 0.3 and then repeattedly pressing 3 until you see a left habd arrow on the display line. If you press equals, then the calculator will display the fraction equivalent of the decimal. If you have more than one number in the recurrence, you need to repeat that recurrence, again until the left arrow shows, press equals and get the fraction equivalent.

This video features a review of the key features of the HP10s+ calculator.
It includes looking at the different modes available from the Mode menu, inputting and changing between decimal and fraction answers, percentages, indices or exponents and a brief look at the DEL and π key. The HP10s+ has three modes to complete calculations with. COMP or computational mode for general calculations. and then two statistical modes, one for standard deviation and one for regression.

As with many other models of calculator, you can switch the angle units between degrees, radians and the lesser used gradians. You can alter how numbers are displayed, including switching between decimal and scientific notation and display mode lets you change between displayingan improper fraction or a mixed number in the first instance.

One of the best features of the HP10s+ is that if you are working with decimal numbers then you will get a decimal answer in the first instance.

The fraction button enables you to switch this to a fraction answer if required. The reverse is also true. Input fractions or mixed numbers and you get a fraction (or mixed number) answer in the first instance.

The percentage button is a little trickier. It is best to input a percentage sign at the end of your percentage calculation to get the correct answer. This may be due to the % function being coupled with the equals button.

The next example is one third. If you use SD to switch to a decimal, you get a recurring decimal in the first instance. This is 0.3 with a dot above the recurring part, in this case the 3. On some models, particularly the US model of this calculator, the 300ES Plus, have a line above the recurrence instead of a dot. Press SD again and you get a full calculator display decimal approximation.

You can change surds or radicals to decimals as well. If you input a surd such as √5 and press equals, the calculator will repeat that surd back to you. This is beacuase it presents the exact answer in the first instance. If you press SD then you get a full calculator display decimal approximation. The calculator also automatically simplifies surds. For example...

√20 = √4 x √5 = 2 x √5 = 2√5

The calculator will do this simplification automatically and then you can press SD to get a decimal answer. The calculator also gives exact answers involving π in the first instance. You need to press SD if you would like a decimal approximation that you can round.

You might notice in the video I sometimes refer to a decimal approximation. When you have an irrational decimal number (a decimal number that doesn't end), the number will be rounded to the full calculator display. This will only ever be an approximation, but two about 9 decimal places, so this is usually accurate enough for most calculations you may encounter at GCSE or A level maths.