A walking trail is 1 km long . Cecilia has walked the first 20 m .
We know 1 km = 1000m
Cecilia has walked the first 20 m.
Walking trail is 1 km so its 1000m.
Already walked 20m so we subtract 20 from 1000
1000 - 20 = 980 m
To convert 980 m into km we divide by 1000
She has to walk 0.98 km further on the trail