What is 7/8, 0.98, and 8/9 in order from least to greatest

Do you have a calculator? If you do then 7/8 is 0.875 and 8/9 is 0.8 recurring.
For 7/8 and 8/9 you need to find the LCM of the denominators which in this case is 72, multiple 7/8 by 9 and 8/9 by 8 (multiply the top and the bottom by the number). This gives 63/72 and 64/72. So 8/9 is bigger.
0.98 is 0.98/1 so if you multiply that by 8 even without a calculator you'll know that it will be more than 7 so the fraction itself is bigger than 7/8, and the same for 8/9.

So the sequence will be 7/8, 8/9, 0/98.