# Basic Calculator Skills

Here are some instructions for the basic calculator skills every student should have when they start using scientific calculators (between grade 6 and grade 8). These skills are for the use of the EL-W535HT scientific calculator recommended for school users.

### Switching the EL-W535HT scientific calculator on and off:

To switch the calculator on press the  button on the top right hand side underneath the screen.

To switch the calculator off, first press  button on the top left hand side underneath the screen and then press the  button.

### Editing and deleting in expressions

You can use your arrow keys to direct the cursor in the expression. If you want to delete something, move the cursor so that it is flashing behind the number or sign and press the button that says  (which stands for back space).

If you want to go back to the very first equation typed into the normal mode press  and then . This will take you back to the very beginning of all the expressions typed into the calculator that are still stored in memory (remember the calculator will save the last 340 characters of expressions typed in).

If you want to go back to the last expression typed in press   .

If you want to edit something at the beginning of an expression and dont want to press the  lots, press  and then the  button, and it will take you back to the beginning of the expression. Press   to go to the end of the expression.

### Adding, Subtracting, Multiplying and Dividing Integers:

On the Sharp EL-W535HT calculator there are two minus buttons. The one next to + is the function of subtracting or taking away . The one to the left of the equal button means that the value of the number is negative – .

Here is an example:  -5 – (-6). To type this in press

### Fractions

#### To add fractions: two improper or proper fractions –

type in the numerator press the  button and then type in the denominator. Then press the   to get out of the fraction and continue.

Alternatively, first press the  (fraction) button, and then type in the numerator. Press the   arrow key to go the denominator. Type the denominator in and then press   to get out of the fraction and continue.

e.g. 1/2 + 5/3

Press

This should give you an answer of 2 and 1/6. Press the  button to change from a mixed fraction to an improper fraction and press it again to get a decimal so 2 and 1/6 becomes 13/6 becomes 2.166666667. If you press the change button again it will take you back to the mixed number fraction again.

#### To use Mixed number fractions:

If you want to type in a mixed number fraction first type in the whole number. Then press  . Now type in the numerator, press  to get to the denominator and type it in. Then press the  button and continue with your sum.

For mixed number fraction calculations, it is very important to attach the whole number to the fraction by  first pressing the  key.

### Percentage calculations

#### 1. Adding and Subtracting a percentage

When we want to add or subtract a percentage of a number to (or from)  itself – type in the number press either  or   and then type in the percentage. Then press     and the calculator will automatically calculate the percentage added or subtracted.

E.g. 250 plus 25% – – – – type in           which should give you 312 and 1/2.

#### 2. Multiplying and dividing by a percentage

Type in the value you are multiplying first (this is very important) then  or  button. Type in the percent value and then press    and it wil give you the answer.

E.g. 25% of 250 – – – – – Type in          which should give you 62 and 1/2

### Saving a number to memory and using memory keys

Let’s save the last answer (62 and 1/2) to do this press the  and choose the memory letter (A – F, M, or X or Y) and press that button. For example, if I wanted to store into the B memory I would press . The screen should now say ANS => B.

There are two ways to use this memory value. If you want to remember what you have stored into the memory key press the  button and then the memory key.

If you want to use the memory letter in an expression – e.g. 2B + 3 – then you need to type in the expression and when you want to write the memory letter press  and then the memory button.

For this example you would type in       which should give you (if you saved B as 62.5) the answer of 128.

### Finding the prime factors of a number

Type in the number you would like to find the prime factors of and press . Then press  and  and the calculator will automatically find the prime factors of the number for you.

For example find the prime factors of 216. Type in       and you should get the answer of 23x33.