If you mean "1 and 7 meters" as 1 + 7, which is 8, then this would be my work:
1.) So, I know that there are 100 cm in 1 meter.
2.) 8 x 100 = 800 cm in "1 and 7 meters".
3.) The answer I got is 800 cm.
I'm not sure if the answer is correct, but this is the best I can do (I'm only in 7th grade!). I hope this helps, and have a good night! :D