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.
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.
To subtract 0.5 from 0.05, you can think of it as 0.05 - 0.50, which is equivalent to -0.45. To perform the subtraction, align the decimal points of the two numbers and subtract as you would with whole numbers. In this case, you would borrow from the 0 in the tenths place, making it 0.0, and add 10 to the hundredths place, resulting in 15 - 50, which equals -45 hundredths or -0.45.
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