b[0]);
          b = pick(ranges[diff].sub[1]);
          if (a < b) [a, b] = [b, a];
          ans = a - b;
          text = `${a} ${symbols.sub} ${b} =`;
        } else if (op === 'mul') {
          a = pick(ranges[diff].mul[0]);
          b = pick(ranges[diff].mul[1]);
          ans = a * b;
          text = `${a} ${symbols.mul} ${b} =`;
        } else if (op === 'div') {
          const divisor = pick(ranges[diff].div[0]);
          const quotient = pick(ranges[diff].div[1]);
          a = divisor * Mat