meet it

Ruby is a calculator that never gets tired.

+ adds, - takes away, * multiplies and / divides. Each of these signs is an . As in school maths, * and / happen before + and -, unless you use brackets.

Watch out with /. Divide one integer by another and Ruby gives a whole number, dropping what is left: 7 / 2 is 3. A number with a decimal point is a . Write 7.0 / 2 to get 3.5.

% gives the remainder, what is left over after sharing into equal groups. Share 7 sweets between 2 friends and 1 is left, so 7 % 2 is 1.

puts 2 + 3 * 4
total = (2 + 3) * 4
puts total
puts 7 / 2
puts 7.0 / 2
puts 7 % 2

Mix an integer and a float and the answer is a float, so 3.0 * 2 is 6.0.

guess first

Ten shared by four. What will Ruby say?

Guess before you run it. Wrong guesses are how you learn, and nothing is marked.

puts 10 / 4

your turn

Your turn. Share out the pizza.

Type how many pizzas you are ordering, then how many friends will share them (not 0). Each pizza has 8 slices. Run it to see the slices, each share and what is left over.

Your code

press run to see what happens

fix it

Seven cakes for two friends should be 3.5 each. Fix it!

Broken code to fix

press run to see what happens

Run it. Why does Ruby show a whole number instead of 3.5?
Both values are integers, so / drops the part left over. One of them needs a decimal point.
Change line 1 to cakes = 7.0, then press run.

nailed it

you turned ruby into a calculator. :D

* and / come before + and -, unless there are brackets.
Integer divided by integer drops the leftover part.
% gives the remainder after sharing.

new words in your collection

operator
float

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