Find the value of each expression mentally.

Lin and Han are both finding the value of .
Look at how each student started.
What should they do next to find the value?
Write equations to represent your thinking.

1. Lin started by putting 3 tens and 5 tens together.
   She recorded her first step like this: .

2. Han started with 54 and added 3 tens.
   He recorded his first step like this: .

Find the value of using Lin’s or Han’s method.
Show your thinking using equations.