Subtraction -
Addition +
100

90 - 30

60

100

100 + 200

300

200

520 - 20

500

200

600 + 300

900

300

670 - 10

660

300

300 + 700

1,000

400

398 - 30

368

400

200 + 900

1,100

500

874 - 20

854

500

340 + 52

392