Normally, you would subtract it.
You can add or subtract it as a whole number. If you must use its decimal form, you just stick a decimal point at the end the whole number!
The problem would not end
Start with n, then you get; Add 17: n + 17 Double it: 2n + 34 Subtract 4: 2n + 30 Double it: 4n + 60 Add 20: 4n + 80 Divide by 4: n + 20 Subtract 20: n which is where you started.
To subtract 0.5 from 0.05 first line up the decimal points in your equation. If you need to add a zero behind the 5 in 0.5 so you get 0.50. Then subtract as if there was no decimal point (take it as 50-5). After you subtract bring the decimal point down. You should end up with 0.45.
Its easy, dont worry about the decimal and do regular subtraction and at the end just add the decimal right under all the other decimals.
18,21,17,20,16,19,15,18
When using front-end estimation, we add or subtract the front digits, and then adjust for a more accurate estimation by estimating the sum of the digits to the right of the decimal point.
I like this one.... think of a number multiply by 2 add 12 subtract 4 divide by 2 subtract the number you thought of and the answer is 4 it always works its a mathematical certainty once you have the number 4 you can add subtract etc to your hearts content and make any new number provided you remember the answer yourself.
well, its usually a numerical problem where you will probably end up adding the numbers together to end up with the correct answer. Of course the alternative to this, the subtracting probability, is where you would probably have to subtract to end with the correct solution.
Pick a number between 8 and 20. double that number. subtract 16 from that answer. Multiply that result by 4. Divide that total by 8. add 15 to that answer. subtract the number that you started with.
The end result is: -2 + s
y = n - 8 In this case you start with n and then subtract 8. For the inverse operation you start at the end and replace each operation by its inverse. So "subtract 8" is replaced by "add 8". That is it. n = y + 8