## Task 2

Check! Who is calculating correctly? Correct if necessary.

1. Karin: $70+a=120 \quad \Rightarrow \quad a=140$
2. Sven: $b+700=1400 \Rightarrow b=700$
3. Kay: $430-d=370 \quad \Rightarrow \quad d=50$
Sven calculates correctly. Karin calculates incorrectly, the correct answer is $a=50$. Kay also makes a mistake. The correct answer is $d=60$.