.item-missing-number-container {
  height: 100%;
  position: relative;
}

.equation {
  position: absolute;
  transform: translateY(-50%);
  left: 5vh;
  right: 5vh;
  top: 50%;
  font-size: 12vh;
  text-align: center;
}

.missing-number {
  border: 3px solid #d6d4d5;
  width: 12vh;
  display: inline-block;
}