code: function evaluateAndRound(node) {
    let result = node.eval();
    if (result < 1) {
      result  = parseFloat(result.toPrecision(4));
    }
    else {
      result  = parseFloat(result.toFixed(4));
    }
    return result;
  }
docs: Evaluates a math expression to a constant, e.g. 3+4 -> 7 and rounds if necessary