Proportion and Ratio

Proportion-01: simplify a ratio (option to decide the difficulty of simplification, whether to allow ratios that are already in their simplest form, and whether to allow three-part ratios)
Proportion-02: given a ratio and one quantity, calculate the values of the other quantity (or quantities) to preserve the ratio (option to decide the scale factor, whether to allow ratios that are already in their simplest form, and whether to allow three-part ratios)
Proportion-03: proportional circles (where the numbers in each row and column increase in proportion with each other). Find the number in the missing circle (option to determine whether the scale factor is integer, basic decimal or potentially recurring decimals)