Count dots on 5 black and white cards as one input (without a loop)

Challenge Level: Growing experience

This programming challenge is linked to the following lessons:

Challenge 4.3 for How binary digits work (8 to 10)

Learning outcomes

Students will be able to:

Demonstrate how indexing to access a letter at the specified position in a string works.
Computer Science: Programming
Describe how variables store values and how they are used in your program.
Computer Science: Programming
Explain what you need to consider if you are asking for an input from the end user.
Computer Science: Programming
Identify when to use an if statement to check a set of conditions.
Computer Science: Programming

Requirement:

Write a program that asks the end user to enter 5 black and white cards representing bits, all as one line of input ('B' for black and 'W' for white), and displays the total number of dots as the output. You can do this without a loop, using 5 similar sets of blocks to process each of the 5 values.

Testing examples:

Your program should display the outputs shown in this table for the given inputs provided:

Input	Output
WWBBB	24
BBBBB	0
WWWWW	31

Languages

Scratch

What it should look like

Click on the green flag, enter the inputs provided in the “testing examples” to see the expected output of your program.

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Recommended blocks

Hints

Make a variable called “total number of dots” and set its value to 0. Make a string variable called “cards” and set its value to the input entered by the end user (5 black and white cards). Check each letter of the string and if it’s ‘W’ add the corresponding number of dots (16 for the first letter, 8 for the second letter and so on) to the “total number of dots”. Display the “total number of dots” as the output.
You can access a letter at the specified position in a string by using the block under “Operators”. For example:

Show Scratch solution

Python

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Block-based

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