Quick and Dirty $$ How do you calculate the prime numbers below $10?50?100?$ Use Excel to try to produce a solution. Count how many additions, subtractions, divisions and multiplications.

Can we make it more efficient? After you did $2$s$,$ do you have to do $4$s$,6$s$,8$s$...?$ How do you track them? Are there any other rules of thumb observations you can see to improve your algorithm?

What if you were told that division and multiplication are $100$ times slower $($more expensive$)$ than addition and subtraction? Can that effect your program?

To Do:

Create a Quick and Dirty pseudocode to solve this problem. $*$Version $1*$

Copy and paste version one and call it version $2.$ Modify version $2$ in the next step.

Revisit your code to see if it can be done more efficiently. $*$Version $2*$

Copy and paste version $2$ and call it version $3.$ Modify version $3$ in the next step.

In a Breakout room with one or two classmates, compare solutions by talking about them. No showing your solution. $*$Version $3*$

Write the names of the other people in your breakout room.

What were the observations you had?

Were there any observations you can apply to your algorithm?

Critical thinking: how do you measure your algorithms efficiency? We call this a metric.