1. Global Challenge
Walking for Water
Lesson 2

2. Recap questions What are some benefits of walking?
How many steps does the NHS recommend we walk everyday?
Why do we walk less than we used to?
What are the advantages and disadvantages of us walking less?
How far does Aysha walk every day?
What is the ‘Water Burden’?
How does having to walk for water impact on Aysha’s life?
What is your challenge?

3. Walk as many steps as Aysha does in 1 day over 4 days.
Your challenge
Walk as many steps as Aysha does in 1 day over 4 days.

4. Learning objectives:
to use decomposition and abstraction effectively to solve a problem
to write, test and debug accurate algorithms and programs
to use iteration, loops and variables to write efficient algorithms and code

5. The first part of the challenge
create a step counter using micro:bit

6. Think: what do we need to do to complete this part of the challenge?
what tasks?
in what order?

7. Decomposition Algorithm Abstraction
breaking down a complex problem into smaller, component parts.
Algorithm
a sequence of instructions or rules to solve a problem
written for a person to follow to write code
Abstraction
focussing only on the important parts
filtering out unnecessary detail

8. Programming Testing & debugging Iteration Variables
using an algorithm to write code a computer can understand
Testing & debugging
regularly checking for, finding and correcting errors
Iteration
The repetition of a sequence. Loops are a form of iteration (repeat until a certain condition is met)
Variables
used to store information, e.g. number of steps

9. Pseudocode A simple way of describing an algorithm
No specific syntax (programming language)

10. Step tracker example algorithm
On START
Set ‘steps’ to 0
OUTPUT ‘steps’ on visual display
REPEAT forever
When sense movement
add 1 to ‘steps’

11. Paired programming 2 programmers working together to code
One types the code (driver)
One watched the driver, checks the code, makes suggestions (navigator)
work collaboratively, talking through problems
Why might this be helpful?
more accurate code written in shorter time
can collaboratively work through problems

12. Sample step tracker example code

13. Learning objectives:
to use decomposition and abstraction effectively to solve a problem
to write, test and debug accurate algorithms and programs
to use iteration, loops and variables to write efficient algorithms and code