Easy numbers Addition (Basics)

Generally for peoples making addition is easier than subtraction. We will learn how to make addition even more easier.
>How would you add 68 plus 9 in your head?
The easy way would be to add 10 to 68, (78), and take away one (1). The answer will be 77.
It is easy to add 10 to any number mentally; 27 plus 10 is 37; 249 plus 10 is 259, etc. Simply increase the tens digit by 1 each time you add 10 to a number.
Here is a basic rule for adding mentally :

To add 9, add 10 and subtract 1; to add 8, add 10 and subtract 2; to add 7, add 10 and subtract 3, and so on.

If you wanted to add 36 , you would add 40 and subtract 4 . To add 295, add 300 and subtract 5. This makes it easy to calculate mentally. To add 67 to a nubmer, add 70 and subtract 3 . To add 385 to a number, add 300 and subtract 15.



Now try these quickly in your head. Call out the answers. For 57 + 9 , don't call out, "sixty-seven, sixty-six". Make the adjustments in your head while you call out the answer. Just say, "sixty-six". Try the following examples ( don't worry, Hints are given to help you out in case you need assistance )

a) 89 + 8 = ? [Hint: Add 10 to 89 and subtract 2 from it. Step 1 > 10 + 89 = 99 , Step 2> 99 - 2 = 97 (Your final answer) .]
b) 75 + 9 = ? [Hint: Add 10 to 75 and subtract 1 from it. Step 1> 75 + 10 = 85, Step 2> 85 - 1 = 84 (Your final answer).]
c) 54 + 7 = ? [Hint: Add 10 to 54 and subtract 3 from it. Step 1> 54 + 10 = 64, Step 2> 64 - 3 = 61 (Your final answer).]
Self-exercises :-
a) 76 + 9 = ?
b) 153 + 8 = ?
c) 278 + 6 = ?
d) 95 + 8 = ?

Also check out Easy Three-Digit numbers addition ..