40

160

80

200

670

700

350

300

9,000

8,700

8,720

3

5

13

21

10,800

1,100

100

700

1,250

3

4,000

2,200

45

There are many suitable answersHere are some:

149 153

348 352

247 251

10 + 30 = 40

multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78 ...

66 ÷ 6 = 11 72 ÷ 6 = 12

11 or 12

200,000

150,000

153,000

5,000,000

5,200,000

5,250,000

5,246,000

0.3

3.6

8.1

25,500

26,499

Primes2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31 ...

29 x 20 = 58031 x 20 = 620 both round to 600

29 and 31