CAUTION: Begin grouping on the left, that is, by higher values
This exercise consists of grouping the numbers into sets of 10 units and then adding them.
In this exercise you must indicate which rod is necesary to complete 10. Remember the friends numbers.
Two numbers are friends if between numbers sum 10
5 and 5
(The number five is a friend itself)
6 and 4
(We can draw a number four if you rotate 90° the number six)
7 and 3
(the number 7 is drawed with 3 lines)
8 and 2
(the number 8 has two holes)
(the number nine has one hole)