Cal. Rev. & Tax. Code § 10759

In computing any fee, offset, or penalty imposed by this chapter, whether on a proration or otherwise, a fraction of a dollar is disregarded, unless it equals or exceeds fifty cents ($0.50), in which case it is treated as one full dollar ($1). Computation of any penalty shall be made from the fee after the same has been computed as provided in this section.

Any fee, offset, or penalty in an amount of forty-nine cents ($0.49) or less shall be deemed to be one dollar ($1).