calculate the number of ATP molecules synthesized in glycolysis by the partial oxidation of one molecule of glucose

During glycolysis, two molecules of ATP are consumed during double phosphorylation of glucose to form fructose 1,6 biphosphate. In return four molecules of ATP are formed during conversion of 1,3-biphosphoglycerate to 3-phosphoglycerate and phosphoenolpyruvate to pyruvate. Two molecules of NADH are formed at the end of oxidation of glyceraldehyde 3-phosphate to 1,3-biphopshoglycerate. Each NADH molecule produces 3 ATP molecules.
Hence, total number of ATP molecules formed  = 4-2+6 = 8