Is the word dez the same in Brazilian and European Portuguese?

Yes

The spelling, meaning, and grammatical function of "dez" are identical in both Brazilian and Continental Portuguese. The only difference is the pronunciation of the final consonant:

• In Brazil: The "z" is typically pronounced as an [s] sound (e.g., dɛs).
• In Portugal: The "z" is typically pronounced as a [ʃ] sound (the "sh" sound, e.g., dɛʃ).

Brazilian Portuguese Examples:

1. Eu tenho dez reais no bolso. (I have ten reais in my pocket.)
2. São dez horas da manhã. (It is ten in the morning.)
3. Ele fez dez anos ontem. (He turned ten years old yesterday.)
4. Comprei dez bananas na feira. (I bought ten bananas at the street market.)
5. Tem dez pessoas na minha sala. (There are ten people in my classroom.)

European Portuguese Examples:

1. Tenho dez euros na carteira. (I have ten euros in my wallet.)
2. São dez horas da manhã. (It is ten in the morning.)
3. O meu filho já tem dez anos. (My son is already ten years old.)
4. Comprei dez maçãs no supermercado. (I bought ten apples at the supermarket.)
5. Há dez pessoas na fila. (There are ten people in the line.)