Respuesta :
Answer:
100
1800
900
1600
Step-by-step explanation:
Easy way to solve :
remove the 0's eg
20*90 -> 2*9 = 18
then add the 0's back on
1800
Answer:
See below ↓↓↓↓
Step-by-step explanation:
- 10 x 10 = 100
- 20 x 90 = 1800
- 30 x 30 = 900
- 40 x 40 = 1600