Numeral adjective ogdoēkonta (eighty) in the New Testament

(Translation from NRSV)

Luke

2: 37then as a widow to the age of eighty (ogdoēkonta)-four. She never left the temple but worshiped there with fasting and prayer night and day.
16: 7Then he asked another, 'And how much do you owe?' He replied, 'A hundred containers of wheat.' He said to him, 'Take your bill and make it eighty (ogdoēkonta).'