As part of a modeling problem, I asked a student to

determine t such that 20 * 10^t = 1000. Since this student

does not yet know about logarithms, we're using the bisection 

method to automate the trial and error process.

​

I haven't taught loops or functions yet, so this program 

contains only the basic logic. However, it can be used 

to get an answer through manual iterations (typing in

new bounds based on the output, running again, and repeating 

until the size of the search interval is as small as desired).

*/

​

let a = 1; //lower bound of search interval

let b = 2; //upper bound of search interval

let m = (a + b) / 2; //midpoint of search interval

let y = 20 * (10 ** m); //y-value at midpoint

​

if (y < 1000) { //midpoint is too small

  a = m;        //set lower bound to m

}

else {          //midpoint is too big (or it's correct)

  b = m;        //set upper bound to t

}

​

console.log(a); //log new lower bound

console.log(b); //log new upper bound

console.log(b - a); // log size of search interval