5: Early Additive - Addition and Subtraction

 

Juanita has 8 coloured pencils. She gets 5 more coloured pencils. How many does she have now?


(enlarge)

Student: Eight plus two from the five equals ten. Ten plus three more equals thirteen.
Teacher: Could you work it out a different way?
Student: You can take the five, plus five from the eight and that makes ten, and then there are three more.

Click here for video

At the Early Additive stage, students have begun to recognise that numbers are abstract units that can be treated simultaneously as wholes or can be partitioned and recombined. This is called part-whole thinking.