Lesson 2 of 12

Blocks and arrows: your first program

Build your first program from flowchart blocks: Start, Tell and End, joined with arrows. Press Run, or Step to watch each block, and see the code it makes.

About 5 minutes · 3 parts, each with a program to try

Part 1 of 3

Every program begins at Start and finishes at End

A new program already has a Start block. Add blocks under it, join them with arrows, and finish at End.

The smallest useful program has one block in the middle: a Tell that shows a message.

ExampleHello World Try it

Start
Tell "Hello World"
End

It showsHello World

1print("Hello World")

Part 2 of 3

Tell shows a message

Words go inside "quotes": "I am learning to code". Without quotes, Tell works things out: 7 * 6 shows 42.

Join words and values with +: "Score: " + 10 shows Score: 10.

ExampleWords and sums Try it

Start
Tell "I am learning to code"
Tell 7 * 6
Tell "Score: " + 10
End

It showsI am learning to code42Score: 10

1print("I am learning to code")2print(7 * 6)3print("Score: " + str(10))

Part 3 of 3

Join blocks, then Run or Step

To join two blocks, drag from the dot at the bottom of one to the next. Click the + on any arrow to slip a new block in between.

Run plays the whole program. Step runs one block at a time, and the block that's running glows, so you can watch it think.

ExampleStep through it Try it

Start
Tell "One"
Tell "Two"
Tell "Three"
End

It showsOneTwoThree

1print("One")2print("Two")3print("Three")

Blocks in this lesson

Start Tell End

Quick check

Which Tell shows the word Hello on the screen?

Practise this

World 1 challengesBuild it yourself, with three hints each.🏠 Rahul's MorningA Story Mode story that uses it.