Remember: What you do to one side of the equation, you do the opposite to the other side.
Remember: Keep the gap the same!
What you do to one side of the equation, you do exactly the same to the other side.
What happens when one number is close to 100? (subtraction)
What strategy can you use when numbers are nearly the same?
What strategy can you use when adding three or more numbers?
What happens when we have 1o or more?