This program is running the functions too many times. When you run a function save the result into a variable, then pass that variable into the other functions as input parameters.

Can you fix it like the comment above?

"use strict";

// Use document.getElementById to read the prices of the 3 elements from the DOM: back-price, calc-price, and text-price.

function showItems() {

const backPrice = document.getElementById("back-price");

const calcPrice = document.getElementById("calc-price");

const textPrice = document.getElementById("text-price");

// Use the textContent property of the elements to read the text contents from the 3 DOM elements.

let backpackPrice = backPrice.textContent;

let calculatorPrice = calcPrice.textContent;

let textbookPrice = textPrice.textContent;

let pricestax = [backpackPrice, calculatorPrice, textbookPrice,];

return pricestax;

}

// Cal total items price

function calcSum() {

let subTotal = 0;

subTotal = Number(showItems()[0]) + Number(showItems()[1]) + Number(showItems()[2]);

return subTotal;

}

// Declare tax rate

function taxRate() {

const taxRate = 0.13; // The bookstore charges 13% sales tax.

return taxRate;

}

// Cal sale tax

function calcTax() {

let taxAmount = 0;

taxAmount = calcSum() * taxRate();

return taxAmount;

}

// Cal final cost

function calcfinalCost() {

let finalcostAmount = 0;

let sumitemsAmout = calcSum();

let taxrateAmount = calcTax();

finalcostAmount = calcSum() + calcTax();

//Output the results

document.getElementById("sub-total").textContent = sumitemsAmout.toFixed(2);

document.getElementById("tax-amount").textContent = taxrateAmount.toFixed(2);

document.getElementById("total").textContent = finalcostAmount.toFixed(2);

}

calcfinalCost();