Untitled

TTRS

Spellzone

Numbots

Sumdog

Atom Learning

First take the last digit of a number:

eg: 13824 4 is the last digit

Find which number's cube root is 4. In this case it's 64. Last digit of 64 is 4. That means the last digit of our missing number is 4.

If its a 5 digit number take the first two digits. 4 digit or 3 digit take the first number. 13 is between 2 cubed ( 8 ) and 3 cubed ( 27 ). Therefore our number is between 20 and 30.