What are units?
A unit can be used for measurement, and is commonly found in mathematics to describe length, size, etc.
What is a ratio?
A ratio has two or more numbers that symbolize relation to each other. Ratios are used to compare the numbers, and you can compare them using division.
We first would need to know the ratio of centimeters to meters.
1 centimeter = 0.01 meter
Now that we know this, we can take 120cm (number of steps) and multiply that by 70cm (size of each step).
120 × 70 = 8400
Now that we have the total amount of centimeters, we can multiply that by 0.01 (or divide by 100) to get the number of meters the scout traveled.
8400 × 0.01 = 84
This means that the scout traveled 84 meters.