In this blog post we will use a Python script to work out how many lego bricks would be needed to build planet Earth!

To solve our problem we will use the following data:

We will work out the number of lego bricks needed in several step using a **sequencing algorithm**: An algorithm consisting of instructions that are carried out (performed) one after another.

We will use the following steps:

- Convert all measurement to the same unit (e.g. mm)
- Calculate the volume of planet Earth
- Calculate the volume of a lego brick
- Number of bricks needed = volume of planet Earth / volume of a lego brick

We will need to use the following two formulas:

**The complete flowhchart for our algorithm:**

#### Python Code

You can now code this algorithm using Python to reveal the answer to the initial question: how many lego bricks are needed to build planet Earth!

#### Number of lego bricks

If you have completed this algorithm, the final answer should be approximatively:

^{26}(in standard form)

#### Using subroutines

It is good practice to use subroutines whenever possible as these can then easily be reused in other programs. Your task is to adapt your code by defining a d using two

**functions**as follows:

- Your first subroutine should be called
*getVolumeOfSphere()*, take one parameter called*radius*and apply the relevant formula to calculate and return the volume of a sphere based on the given radius. - Your second subroutine should be called
*getVolumeOfCuboid()*, take three parameters called*width*,*length*and*height*and apply the relevant formula to calculate and return the volume of a cuboid based on the given dimensions.