King James Version (KJV)
And the rest of the trees of his forest shall be few, that a child may write them. {few: Heb. number}
Modern English
The remnant of the trees of his forest shall be few, so that a child could write their number.
Hebrew
וּשְׁאָ֥ר עֵ֛ץ יַעְר֖וֹ מִסְפָּ֣ר יִֽהְי֑וּ וְנַ֖עַר יִכְתְּבֵֽם׃
vshʾar ʿeṣ yaʿrvo mispar yihyv vnaʿar yiktbem