Misfigure

But you make another mistake — you misfigure dates again — and you've got something more to answer for.

Source: wiktionary

You're a Gray-Area Misfigurer when you misfigure accidentally on purpose. Say your 100 shares of a $20 stock go up to $22, so you claim bragging rights to 10% profits. However, when you figure in commission, your shares really cost more like $2,050.

Source: wiktionary

You might argue about letting borderline students squeak through some courses, but who wants a nurse who misfigures her meds?

Source: wiktionary

"Now, see here, mister, you get right back into that brush, a bargain's a bargain and you're not near the tree yet." “But I'se jest—” “Never mind now, you just misfigured a trifle, that's all, and I stay in the open till the tree is reached.”

Source: wiktionary