Единицы измерения массы

{"questions":[{"content":"Переведите $5$ кг в граммы[[choice-1]]","widgets":{"choice-1":{"type":"choice","options":["$5 000$ гр","$500$ гр","$50 000$ гр"],"explanations":["$1$ кг = $1000$ гр","",""],"answer":[0]}}},{"content":"Сколько килограммов в $3$ тоннах?[[choice-7]]","widgets":{"choice-7":{"type":"choice","options":["$3000$","$300$","$30000$"],"explanations":["$1$ тонна = $1000$ кг","",""],"answer":[0]}}},{"content":"Выберите верное утверждение[[choice-15]]","widgets":{"choice-15":{"type":"choice","options":["$1$ кг = $10^{6}$ мг","$1$ кг = $10^{5}$ мг","$1$ кг = $10^{4}$ мг"],"explanations":["$1$ кг = $1000000$ мг","",""],"answer":[0]}}}]}