Here's an easy way to multiply any number in any digits with 11 Lets practice with a 2 digit number first: for example lets take 23 Adds the two digit together example for number 23 is 2+3 = 5 Insert the number between the original number, example 2 5 3, and there you have your answer Ok now what if the number has total adds up to more than ten like for 89 Just adds the two digits ex: 8+9=17 Now insert between the first and the last of the original number with the number 1 being add to the previous number ex: 8(+1) 7 9 resulting 979 and there's your answer. Now for the ultimate, how to multiply number that has more than 2 digit with 11, for example 239: First split the number ex: 2+3 = 5 and 3+9 = 12 Now remember,since the last number has [+]