I agree with him.
1/3 is also 0.3 with a bar over the 3.
If you multiply 0.3 with a bar over the 3 by 3, you get 0.9 with a bar over the 9.
Since 0.3 with a bar over the 3 is the same as 1/3, and 1/3 * 3 = 1, then 0.9 with a bar over the 9 is the same as 1.
