This video looks at how you can use the calculator to work out percentage increase and decrease or percentage change. It makes use of mulipliers and the % button to enable your calculator to work out increased and decreased amounts based on total percentage. You can also use the calculator to find a starting amount, when you know an amount that has been increased by a percentage.

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 most inportant thing to remember when calculating percentages is that your calculator works in decimals. Therefore, to find a percentage, you must use either a decimal equivalent or the percentage button to get a correct answer. You could also multiply by 100 if you prefer. This video shows you haw you can calculate percentages using the percentage button or function. This is a second function which you can access by pressing SHIFt and then the left bracket or parentheses "(" .

In the video, we find 15% of 480 using the percentage button. Input 15 and then pres SHIFt and then (. The percentage sign should appear on screen.

The operator we need to use when we we want to find the percentage OF an amount is Multiply. Of mean multiply in mathematics. Then input 480 and that gives us our answer of 72.

The video then looks at increasing or decreasing by a percentage, in this example 550g is increased by 22%. We can use a percentage multiplier as follows. If 550 represents 100% or our original total then we want an extra 22%, essentiall we want to find 122% in total.

100% + 22% = 122%

Input 122 and press SHIFT and ( for the % sign. Multiply by 550 and it takes you straight to the answer, 671g.