def to_sci_not(f):
    """Convert float `f` to a scientific notation string
    (not including the `$`)
    by using string formats `e` and `g`.
    """
    s_e = f"{f:.4e}"
    s_dec, s_pow_ = s_e.split("e")
    s_dec = f"{float(s_dec):.4g}"
    pow_ = int(s_pow_)
    return f"{s_dec} \\times 10^{{ {pow_} }}"