# Thread: [Highschool math] SIR Model (simulating diff-EQ w/ turtle graphics using JSXGraph)

1. ## [Highschool math] SIR Model (simulating diff-EQ w/ turtle graphics using JSXGraph)

Hello,

I'm trying to understand how to model an infectious disease, I was just wondering how they got this value on this page

How did they get the I(0)=1.27E-6 value?

Thank you!

2. ## SIR Model help

Hello, I m trying to understand how to model an infectious disease, I was just wondering how they got this value on [this page](http://jsxgraph.uni-bayreuth.de/wiki..._The_SIR_model)

How did they get the I(0)=1.27E-6 value?

3. Originally Posted by nawar
Hello, I m trying to understand how to model an infectious disease, I was just wondering how they got this value on [this page](http://jsxgraph.uni-bayreuth.de/wiki..._The_SIR_model)

How did they get the I(0)=1.27E-6 value?
I(0) is defined as the fraction that is infected at time 0. You are given that 10 people of 7.9 million are initially infected. What fraction is that?

4. Originally Posted by nawar
Hello,

I'm trying to understand how to model an infectious disease, I was just wondering how they got this value on this page

How did they get the I(0)=1.27E-6 value?

Thank you!