def get_place_values(places):
    # type: (int) -> tuple
    """Get values of `a`, `b`, and tolerance for decimal `places`

    Returns:
        tuple[float, float, float, float] --
            (`b - tol`, `b`, `b + tol`, tolerance)
    """
    diff = 1.0 / pow(10, places)
    eq_val = float('1.' + '0' * max(1, places))
    lt_val = eq_val - diff
    gt_val = eq_val + diff

    return lt_val, eq_val, gt_val