Answer: Ela has 500 pennies in all.
Explanation:
Ela has pennies in each stack = 10
Total number of stacks Ela has = 50
The total number of pennies Ela has in all=10+10+10+10...........[50 times]
Now, to find total pennies Ela has in all, we multiply pennies in one stack to the total stacks Ela has, we get
The total number of pennies Ela has in all

Therefore, Ela has 500 pennies in all.