The following sentence is extracted from a CR question, OG11-55:

One government program would award low-income families a refund on the income taxes they pay of as much as $1,000 for each child under age four.

I don't understand how "of" is used here. Any ideas?

Thanks.

perhaps, it's "off"?

thus, the main sentence is following:

One government program would award low-income families a refund on the income taxes they pay off as much as $1,000 for each child under age four.

可以这样理解吗？

...award low-income families a refund （on the income taxes they pay） of （as much as） $1,000...

...award low-income families a refund... of... $1,000...