VIEWS: 956 PAGES: 17 CATEGORY: Accounting POSTED ON: 8/9/2008
This is an example of basic calculator. This document is useful for conducting basic calculator.
What simple calculators can do Clear c.ce Key in 1 + 2 + 3 + 4 You decide you do not want to do this calculation after all… Key in c.ce Now key in the calculation you want to do now: press 1 + 1 = You got the answer 8! c.ce Why? Because when you pressed only your last entry (4) was cleared. If you want to start another calculation, you need to press = so that the total appears in the display before you clear. Directed numbers +/- To calculate –4 + 5 = Key in 4 +/- + 5 = To calculate –4 x 9 = Key in 4 +/- x 5 = Memory r.cm m- m+ Key in your age (or any other favourite number). Press m+ c.ce Now do a calculation e.g. 37 x 49 = Press c.ce Press r.cm Your age should now be displayed as it was held in the memory. r.cm To clear memory, press twice and once. c.ce Memory r.cm m- m+ To work out the answer to a calculation such as (4 x 4 ) – (3 x 3 ) Key in 4 x 4 m+ c.ce Then 3 x 3 m- r.cm Simple calculators calculate “as you go”. Without the use of the memory the calculation would be interpreted as 4 x 4 – 3 x 3. On a simple calculator this would work out as 39 as each operation is completed as it is entered into the calculator. Scientific calculators wait for = before calculating the answer and carry out operations in order of “priority”. The constant function Key in 1 + = then keep pressing = The calculator continues to count on in steps of 1, starting at 1. Key in then keep 1 + = 0 pressing = The calculator counts on in steps of 1, starting at 0. Key in 2 + = 0 then keep Pressing = The calculator counts on in steps 2, starting at 0. Key in 1 + 2 = 1 then keep pressing = The calculator counts on in steps of 2, starting at 1. Percentages To find 10% of £25 Key in 2 5 x 1 0 % DO NOT PRESS = Was To work out a discount £36.99 20% off Key in 36 . 99 - 20 % DO NOT PRESS = The display shows the discounted price. To find how much the discount was. Key in = The display now shows the discount. To add V.A.T Key in 2 9 . 5 9 + 1 7 . 5 % Making a number machine Key in 5 + 2 = The calculator displays the answer. Key in 8 + = What has the calculator done? Try entering some more. You calculator is a number machine! The Square root key √ To find the square root of a number, enter it and press √ Key calculator skills for year 5 I know how to clear the display before I start a calculation, including clearing the memory. I can set up the appropriate number of decimal places. I can use the [+], [-], [x] and [÷], the [=} key and the [.] key to calculate with realistic data. I use the [clear entry] key to change an accidental wrong entry rather than [clear all]. I recognise a negative number output. I know how to check what the last operation I used was. I know how to recall an answer that has been stored. I can key in and interpret money calculations, including changing all amounts to the same unit. When I calculate money problems by turning all amounts into pence, I can change the total back into £. I am beginning to select the correct key sequence to carry out calculations involving more than one step e.g. 8 x (37 + 58) I know that a number such as 81.75 is more than 81 and less than 82. I can interpret a number such as 6.9999999 as 7 and know why these numbers sometimes appear. I have a feel for the approximate size of the answer. I check answers by repeating the calculation or by performing the inverse. I know how to “show my working” when I have used a calculator to work out an answer. Key calculator skills for year 6 I can use the [clear] and [clear entry] keys, all operation keys, the [=] and [.] to calculate with realistic data. I recognise a negative number output. I use the [sign change] key where appropriate. I can key in and interpret the outcome of calculations involving sums of money. I can key in and interpret other measurement calculations such as length, mass, capacity and time. I can key in fractions, recognise the equivalent decimal form and use this form to compare and order fractions. I know that figures such as 0.3333333 are read as “point three recurring”. I know that 0.3333333 represents one third and that 0.6666666 represents two thirds. I have begun to use the memory keys for calculations involving two sets of brackets e.g. (23 + 41) x (87 + 48) I have a feel for the approximate size of an answer and check it appropriately. In situations where it is appropriate, I choose to use the calculator for speed even when I could use pencil and paper methods. I recognise questions where the use of a calculator is appropriate. I know how to “show my method” on paper when I have used the calculator. Key calculator skills for year 7 I can use the [√] and [ 2] keys. I can use the [%] key. I am aware that basic and scientific calculators work differently and choose the appropriate way of working for the different types. I use the [sign change] key where appropriate I can key in some measurements of time, as decimal amounts e.g. 4 hours 15 minutes is 4.25 hours. I can use the memory and select the correct key sequence to carry out more than one step, including calculations involving division e.g. 364 ÷ (23 + 17) I know how to use the bracket keys on a scientific calculator. I can key in fractions, recognise the equivalent decimal form, and use this to compare and order fractions. I can use the constant function. I have a feel for the approximate size of an answer and check it appropriately. I can input a negative number and recognise a negative number in the display. I can interpret the display in the context of a problem e.g. 109.2 could mean £109.20 or 109 metres and 20 centimetres or 109 minutes and 12 seconds. I read a display of 91.3333333 as 91 point three recurring and know that 0.3333333 represents one third. I realise that some calculators may produce rounding errors e.g. 2 x 7 ÷ 7 = 1.9999999 instead of 2 I know that if, for example √3 is shown to be 1.732051 then (1.732051)2 ≈ 3 I can convert units of time e.g. 1000 minutes to hours and minutes.