adding negative numbers

1-10 x1

100

1+-6

-5

200

-3+4

1

300

-7+-9

-16

400

-10+5

Double 

-5

500

-9+9

0

10-20 x2

100

12-15

-3

200

17+-2

15

300

-6+19

13

400

-19+13

-6

500

-18+-18

-36

20-30 x3

100

23+-29

-6

200

-20+-20

-40

300

-29+-1

-30

400

-30+6

DOUBLE 

-24

500

-22+2

-20

30-40 x4

100

33+20

53

200

-35+7

Double 

-28

300

-39+-21

-60

400

-23+19

-4

500

39+-10

29

40-50 x5

100

45+-9

36

200

49+-21

28

300

-50+25

-25

400

-29+39

Double 

10

500

-47+9

-38