Part Adder

I used part adder to add 2 digit numbers that were 48 + 49

40 + 40 = 80 

8+ 9 = 17 

80 + 10 = 90 

90 + 7 =

97

I also did another one I worked out 

I worked it out like this

48 + 40 = 88 

88 + 9 = 97

Here is a link to Part adder

http://digistore.tki.org.nz/ec/viewMetadata.action?id=L92