## Task 4 - 110514

The product $21 \cdot 12 \cdot 25$ is to be calculated.

Manfred wants to solve this problem in writing.

Annerose says: "With the help of a computational advantage, I can also solve the problem in my head."

Indicate which computational advantage Annerose could have used!
Annerose, for example, uses the fact that $4 \cdot 25=100$. Since 12 is divisible by 4 (resulting in 3), she can calculate: $21 \cdot 3=63$.

The remaining multiplication by 100 is achieved by appending 2 zeros. The result is thus 6300.