6th GRADE COMMON CORE STANDARDS: RATIOS.- Basic concepts: ratios, equivalent ratios, fractions in its lowest terms, compare ratios, rates, percentages, tables, product of means, units conversion, scales, pi ratio, man proportions, probabilities, index numbers and equations.- Students can follow the app jobs from the beginning to the end pressing the 'next' button. Also, they can look for the desired subject in the index.- Assessment with 13 different tests.- Interactive graphics.