Problem Teachers' Notes Hint Solution

# Four Go

Where on the number line do you want to put a mark? How will you make that answer from the numbers in the grid?
You could use a calculator to check your answers if your opponent doesn't agree!
How will you stop your opponent from getting four in a line before you?
Are there any good places on the number line to start? Are there some places which might not be so good to start? Why?