Rephrase introduction.

Author: xanni

exercises/square-root/introduction.md

@@ -4,6 +4,7 @@ We are launching a deep space exploration rocket and we need a way to make sure
 
 The first step in our coordinate calculation involves taking a number as input and finding another number which multiplied by itself will equal our input number, or in other words, finding the square root of our input number.
 
-Because the journey will be very long, we had to make our rocket’s onboard computer very power efficient so it wouldn’t drain the batteries.
+The journey will be very long.
+To make the batteries last as long as possible, we had to make our rocket’s onboard computer very power efficient.
 Unfortunately that means that we can’t rely on fancy math libraries and functions, as they use more power.
 Instead we want to calculate or approximate the square root directly.