Mr. krogman usually prices the umbrellas in his store $8 each. however, on a rainy day he increases the price by 75%.how much does he charge on a rainy day?

Calculator method:
75% as a decimal is 75/100= 0.75. So an increase of 75% is 100% + 75% which is the same as 1+0.75= 1.75. This is your multiplier, so now just do 8×1.75=$14
Non-calculator method:
Find out what 50% of 8 is, this can be done by halving 8 which gives you 4. Now find out what 25% of 8 is, this can be done by halving what you got for 50% (4), so 25% of 8 is 2. 50%+25%=75%, so (4+2)=6 is 75% of 8. Now just do 8+6= $14
The answer is in bold.

Understanding what? lol