If a garden snail travels 1.5 miles per hour, then when 0 hours pass, it would have travelled 0 miles (no time has passed).
After 1 hour, it would have travelled 1.5 miles.
After 2 hours, it would have travelled 3 miles (1.5 miles × 2 hours).
After 3 hours, it would have travelled 4.5 miles (1.5 miles × 3 hours).
After 4 hours, it would have travelled 6 miles (1.5 miles × 4 hours).
After 5 hours, it would have travelled 7.5 miles (1.5 miles × 5 hours).
I hope this helps!