calculator.js

const price = btcPrices[month];
  if (!price) {
    invalidMonthRange();
    return;
  }

  const lastPrice = btcPrices.lastMonth;

  console.log(`Price for month ${month} was ${price}`);
  console.log(`While the price for the last month was: ${lastPrice}`);

  const roi = (lastPrice - price) / price;
  const grossProfit = roi * amount;

  console.log(`Gross profit now would be: ${grossProfit}`);
  console.log(`ROI: ${roi}`);

  setGrossProfit(grossProfit);
  setROI(roi);