Solving
Alright so we know there are two sticks and that one is 10cm longer than the other. Knowing this information we can start off by dividing the total to make the sticks equal in length.
80cm ÷ 2 = 40cm
^ So currently each stick is 40cm
From here we have to make one stick 10cm longer so we would subtract 10cm from one and add that 10cm to the other one.
Stick 1: 40cm - 10cm = 30cm
Stick 2: 40cm + 10cm = 50cm
Answer
This means that the longest stick is 50cm in length
