7,040,836 what's the value of the digit 4 in this numbers place

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Mario has $14.35 left in his wallet. he spent $148.43 for tablecloths. then, he spent $92.05 for napkins. how much money did mario have in his wallet to start with?

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount