2. Write the missing numbers.

15
 

19
 

23
 
 
 
 
 
 

22
 
 
 
 
 
 
 

29
 
 

52
 
 
 
 
 

55
 
 
 

85

87
 
 
 
 
 
 

3. Write the tens that are between the numbers.

39   41
79   82
89   91
27   31
53   63
75   84
60   40
70   50
90   70
32   28
65   55
89   71