К трем годам он без труда считал до

К трем годам он без труда считал до 100.

Результаты (английский) 1:

By the age of three, he could easily count to 100.

Результаты (английский) 2:

By the time he was three, he could easily count to 100.

Результаты (английский) 3:

At the age of three, he had no trouble counting to 100.