A21 I can add HTU + HTU.

A22 I can add and p.



A23 I can add ThHTU + HTU.

A24 I can add U.t + U.t.



A25 I can add more than two numbers with different amounts of digits.

A26 I can add U.th + U.th.



A27 I can add whole numbers and decimals.

A28 I can add negative numbers in a context (e.g. temperature).