At the ‘predict’ & ‘run’ stages students work entirely with example code. They should inspect it carefully and write a prediction about what it will do.

They then run the code and compare the result to their prediction.

Nesting is the term for putting programming constructs of the same type inside each other.

These examples use nested if statements – if statements inside other if statements.

The nested statement will only be run if the condition above it is True.

if num1 > 20:
  print("Bigger than 20")

# nested if is indented so is part of the 'if' statement above.
  if num1 > 50:
    print("and bigger than 50")
  else:
    print("but not bigger than 50")

• Check the indentation very, very carefully
• Count the ifs & elses, are there an equal number?
• Check your logic, when should each branch run? Is the if statement nested into the correct branch – try drawing out a flowchart on paper to map the possible pathways through the program.