E6

E5

E4

E3

E2

E1

Do basic arithmetic

D6

D5

D4

D3

D2

D1

Read simple letters and figures

C6

C5

C4

C3

C2

C1

Understand simple colors and numbers

B6

B5

B4

B3

B2

B1

Understand simple words

A6

A5

A4

A3

A2

A1

No understanding words

Walk outdoor

Walk indoor

Locomote indoor

Sit

Roll over

No rolling