Question

Peter wants to fence the park in front of his home on three sides which measure 152m 40cm, 205m 10cm, 310m 39cm. What is the total length

Answer 1

One centimenter is 0.01 meters. So, you can write the measures as

$152.40\text{m},\quad 205.10\text{m},\quad 310.39\text{m}$

Once this rewriting is done, getting the total length $T$ is quite trivial, since all measurements are in the same unit, and we can simply sum everything:

$T = 152.40+205.10+310.39 = 667.89$