Question

① $0.192 \times 10$
② $0.39 \times 1000$
③ $100 \times 42.4$
④ $97.57 \times 10$

Explanation:

Step1: Multiply by 10, shift decimal right 1

$0.192 \times 10 = 1.92$

Step2: Multiply by 1000, shift decimal right 3

$0.39 \times 1000 = 390$

Step3: Multiply by 100, shift decimal right 2

$100 \times 42.4 = 4240$

Step4: Multiply by 10, shift decimal right 1

$97.57 \times 10 = 975.7$

Answer:

1. $1.92$
2. $390$
3. $4240$
4. $975.7$