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MATHEMATICAL SHORTCUTSMaths may not be your thing but it is hard to avoid in everyday life, however, help is at hand as there are many shortcuts around that can help make calculations a little easier. Here are just a few ........ For some games with numbers click here TIPS To calculate the total of a bill including tax add 1 before multiplying. Example 1 Price 150.95 plus tax of 0.065 Multiply 150.95 x 1.065 = 160.76 This also works in reverse  160.76 divided by 1.065 = 150.95 Example 2 Price 150.95 plus 17.5% tax Multiply 150.95 x 117.5% = 177.37 In reverse  177.37 divided by 117.5% = 150.95 Thanks to KB for this one. What this is actually doing is acknowledging the original figure is 100% and then adding on the additional percentage or (in this case) tax figure, giving a combined total as an answer. Anything ending in an "even" number is divisible by 2. Anything divisible by 9 is also divisible by 3. Thanks to KB for these. A quick way to do calculations is to drop the noughts at the ends of the numbers then replace them for your final answer. Example  To add 120 + 90 add 12 + 9 = 21 then add back the 0 = 210 If you have to multiply a large number by 25, add two noughts to the number then divide by 4. This is much easier to do, especially mentally. Example: 167 x 25 16700 Divide by 4 = 4175 When faced with a little poser like 27.5% of 50 for example, I find it easier to call it 50% or 27.5. It is easier to mentally divide 27.5 by 2. It works every time. Thanks for these Harvey Alexander When multiplying numbers ending in 5 by themselves e.g. 75 x 75 Deal with the left hand numbers first In this example the lefthand number is 7 Add 1 to this number i.e. 7 + 1 = 8 Multiply the original number 7 x the new number 8 = 56 Now deal with the righthand numbers which are always 5 x 5 = 25 Therefore the answer is 5625 Here is another example  35 x 35 3 + 1 = 4 4 x 3 = 12 5 x 5 = 25 Answer 1225 Thanks to Allan Brown for this contribution To make complex sums easier to handle, break down into simpler elements. Example: 6 x 348
A quick way to convert kilometres to miles is to drop the last digit and multiply by 6. Example: 72 kilometres = 7 x 6 = 42 miles (approximately)
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