There are mainly the following methods to calculate the cross exchange rate:
(1) Same as the direct quote currency

Bid price

USD/JPY: 120.00 120.10

(Cross Division) Bid Price and Sell Price

DEM/JPY = 66.33 66.43

USD/DEM: 1.8080 1.8090
(2) Same as the indirect quote currency

Bid price

EUR/USD:1.1010--1.1020

(Cross division) Bid price and ask price

EUR/GBP = 0.6873 0.6883

GBP/USD:1.6010--1.6020
(3) Direct quote currency and indirect quote currency

Bid price

USD/JPY: 120.10 120.20

(Multiply in the same direction) Buying price and selling price

EUR/JPY = 132.17 132.40

EUR/USD: 1.1005 1.1015