Знаю, что криво, но суть вы уловили.
const summ = {
  element: document.getElementById("summ"),
  clones: [],
  getValue() {
    return this.element.textContent;
  },
  renderClones(selector) {
    if (this.clones.length > 0) {
      this.clones.forEach((clone) => {
        selector.append(clone);
      });
    }
  },
  createClone() {
    const clone = document.createElement("div");
    clone.classList.add(".new-clone");
    clone.textContent = this.getValue();
    this.clones.push(clone);
    this.renderClones(document.body);
  },
  update(value) {
    this.element.textContent = value;
    if (this.clones.length > 0) {
      this.clones.forEach((clone) => {
        clone.textContent = value;
      });
    }
  }
};
summ.createClone();
summ.createClone();
summ.element.addEventListener("click", () => {
  summ.update(3000);
});