In the expression 30+40+70 Jillian added 30and40and then 70 while Samuel added 30 and 70 and then 40 who is correct

First let's find the result of the sum:

30 + 40 + 70 = 140

Now let's review the operations of each one:

Jillian added 30and40and then 70:

30 + 40 = 70

70 + 70 = 140

Samuel added 30 and 70 and then 40

30 + 70 = 100

100 + 40 = 140

answer

both are correct.

Conclusion: the order of the factors does not alter the product.