Year 3 represent numbers in different ways

In Maths we have enjoyed trying to represent numbers in different ways. We have learned that:

“You don’t have to use any numbers at all” -Jack

“People can still understand what you are writing”-Ruan

“A large square means 100”-Noah

“I can do adding with big numbers this way quite quickly” -Phoebe

Can you work out what calculation is on the board?