Tutorial: Math, Comparisons & Logic

Computers are world-class calculators. In this tutorial, you’ll learn how to do calculations, compare values, and combine conditions using simple, everyday English words like and, or, and not.

Step 1: Doing Math

Pith handles regular arithmetic just like you’d write it on paper:

# 1. Addition and Subtraction
items = 10 + 5       # 15
remaining = 20 - 8   # 12

# 2. Multiplication and Division
area = 5 * 10        # 50
half = 100 / 2       # 50

# 3. Negative numbers
change = -15

Controlling Order with Parentheses

Just like in school math, multiplication and division happen before addition and subtraction. If you want addition to happen first, wrap it in parentheses ( ):

# Without parentheses: 3 * 4 = 12, then 2 + 12 = 14
result1 = 2 + 3 * 4

# With parentheses: (2 + 3) = 5, then 5 * 4 = 20
result2 = (2 + 3) * 4

print "Result 1: " + result1
print "Result 2: " + result2

Step 2: Combining Text with +

The + symbol is extra handy in Pith: it also glues text together!

first_name = "Alex"
message = "Welcome, " + first_name + "! Ready to code?"
print message

Output:

Welcome, Alex! Ready to code?

Step 3: Comparing Values

Whenever your program needs to check if two things match or if one number is bigger than another, use comparison symbols. Comparisons always evaluate to 1 (true) or 0 (false).

Comparing Text

You can also compare text directly with == and !=:

user_role = "admin"

if user_role == "admin"
    print "Welcome to the dashboard!"
end

Step 4: Logic with and, or, and not

In some other languages, you have to remember cryptic symbols like &&, ||, and !. In Pith, you write the exact English words you’re thinking!

1. and: Both Must Be True

Use and when both requirements have to be met:

has_ticket = 1
is_open = 1

if has_ticket and is_open
    print "You may enter the concert!"
end

2. or: At Least One Must Be True

Use or when having either option is good enough:

is_weekend = 1
on_holiday = 0

if is_weekend or on_holiday
    print "Time to relax!"
end

3. not: Flip True to False (or False to True)

Use not when you want to check if something is not the case:

is_raining = 0

if not is_raining
    print "Let's go for a walk outside!"
end

Combining Everything Naturally

You can combine them easily using parentheses:

has_id = 1
is_vip = 0
is_banned = 0

if (has_id or is_vip) and not is_banned
    print "Entry approved!"
end

Next Steps

Now that you can calculate and compare values:

• If Statements & Loops: Put your comparisons to work in real programs
• Functions: Package calculations into reusable actions