Addition Problems using Counting On and Magic Ten

A.  Erich Wyne has 4 red teddy bears and Amiel has 6 green teddy bears.  Then Sione checked that Erich Wyne and Amiel had counted their bears correctly.  
How many teddy bears did Erich Wyne and Amiel have altogether?

Jamie and Jacob new that this is an addition problem.
First they counted on from the biggest number.

They added 4 + 6 = 10

B.  April has 12 bears and Cooper has 11 bears.
How many bears do April and Cooper have altogether?

Benjamin and Sonasi used the Magic Ten to answer the question.
They said;
   10 + 2 + 10 + 1
= 10 + 10 + 2 + 1
= 20 + 3
= 23