All of them are termination decimals except for 2/3. This is because all the other decimals end while 2/3 is not terminating. It keeps on repeating. 1/8 is terminating because if you divide 1 divided by 8, you would get .125. .125 is not repeating. It ends. 2/5 is equal to .4. One way to figure out why is the divide the numerator by the denominator. 2 divided by 5 would be .4. 17/50 is terminating as well. If you divide 17 by 50, you would get .34. As you can see, all three of those fractions turned into decimals are terminating. However, 2/3 is not terminating. If you divide 2 by 3, you would get .66666 with a bar on top, indicating it keeps repeating. There are other ways to find out why~
