Number

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What are the two number systems infants use to make judgments about quantities?

Object file system

Analog magnitude system

What is subitization?

Automatic perception, no counting needed.

Just look at something and know there are 3

Numbers 4 or fewer

What are object files?

Use one to one correspondence to decide if more/less/same

Each object is a distinct symbol and the number is figured out by evaluating the files

What is analog magnitude?

Can subitize small numbers because there are great differences between the quantities

Just noticeable difference

Once the numbers get bigger it’s hard to tell the difference

What is ordinality and cardinality?

Ordinality- numbers go in order

Some things are more or less

First sign of number understanding

Cardinality- four objects means four

No matter how bright, far apart, size, or color of the objects

In Wynn’s 1992 study, what is the main claim?

Infants can add and subtract

Look longer if a doll was taken away or if a doll was added

In Wakeley’s 2000 reply, what is the main claim?

He did not find any significant results

Could have been methodological problems