The digit in unit’s place = unit’s digit in the product 1 × 2 × 3 × .... × 9 = 0
The digit in unit’s place = unit’s digit in the product 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8 × 9
See the 5 and 8 from given unit place of product will multiply and give 0 at unit place and then other unit place number will multiply with 0 and final number will be 0 at unit place.
