Show:
x10
x9
x5
Addition
Doubles and Halfs (double points)
100

16x10

160


100

2x9

18

100

1x5

5

100

32+41

73

100

Double of 12

24

200

32x10

320

200
5x9

45

200

12x5

60

200

105+248

353

200

Half of 60

30

300

145x10

1450

300

14x9

126

300

25x5

125

300

67+364

431

300

Double 63. Then double it again.

252

400

320x100

32,000

400

34x9

306

400

36x5

180

400

4,657+332

4,989

400

Half of 268. Then half it again.

67

500

40,003x10

400,030

500

245x9

2205

500

148x5

740

500

556,923 + 5,398

562,321

500

Double 76. Then double it again. Then double it again.

608