Show:
ADDITION
SUBTRACTION
MULTIPLICATION
RATIOS
PROPORTIONS
100

8+3

11

100

7-2

5
100

5x2

10

100

1:3 (in one of the two other forms)

1/3 or 1 to 3

100

1       2 

__ = __

6       x

x=12

200

9+6

15

200

11-3

8

200

7x5

36

200

2/5 (in one of the two other forms)

2:5 or 2 to 5

200

2       6 

__ = __

3       x

x=9

300

15+10

25

300

25-10

15

300

9x11

99

300

9 to 15 (in one of the two other forms)

9/15 or 9:15

300

2       5 

__ = __

4       x

x=10

400

25+25

50

400

75-16

59

400

55x5

275

400

36:2 (in one of the two other forms)

36 to 2 or 36/2

400

4       x 

__ = __

5       15

x=12

500

20+83

103

500

520-115

405

500

96x8

768

500

4/8 is also equal to? 

1/2

500

5       20 

__ = __

6       x

x=24