Effectuer les calculs suivants :

1. \( 3{,}4 + 5{,}6 \)
2. \( 18{,}25 + 12{,}75 \)
3. \( 67{,}8 + 45{,}65 \)
4. \( 9{,}5 - 4{,}2 \)
5. \( 38{,}7 - 19{,}95 \)
6. \( 120{,}5 - 88{,}25 \)
7. \( 3{,}2 \times 1{,}5 \)
8. \( 6{,}3 \times 4{,}7 \)
9. \( 9{,}6 \times 2{,}8 \)
10. \( 27{,}5 \div 4 \)
11. \( 84{,}15 \div 5{,}5 \)
12. \( 39{,}6 \div 3{,}3 \)