Basic facts

1. Half 2=1                                                                      My fastest time was 1:03 seconds
2. Double 9=8
3. Half 40=20
4. Half 200=100
5. Double 100=200
6. Half 90=45
7. Double 10=20
8. Double 70=140
9. Two groups of 7=14
10. 1/2 of 40=20
11. One group of 10=5
12. 9 x 4=36
13. 1/5 of 20=4
14. 1/3 of 9=3
15. 3 x 5=15
16. 10 x 10=100
17. 10 groups of 10=100
18. 7 x 2=14
19. Double 3=6
20. 4 groups of 11=44