9x2=18) 9x3=27) 9x4=36) 9x5=45) 9x6=54) 9x7=63) 9x8=72) 9x9=81) 9x10=90) Multiples of 9. Now it says 9 more than twice a number so you could do like 24 + 24 = 48 + 9 = 57 Now just do that for what ever problem you have just add the numbers together and add 9! Hope this helps! ;D