4 sentences

1. 我算数挺好的。

   wǒ suàn​shù tǐng hǎo de.

   I'm pretty good with numbers.

   Source: OpenSubtitles

2. 这个五岁的孩子已经学会算数了。

   zhè gè wǔ suì de hái​zi yǐ​jīng xué​huì suàn​shù le.

   This five-year-old child has already learned how to do arithmetic.

   Source: Dong Chinese Dictionary

3. 既然签了合同，我们说的话就要算数。

   jì​rán qiān le hé​tong, wǒ​men shuō de huà jiù yào suàn​shù.

   Now that we've signed the contract, we must stand by our word.

   Source: Dong Chinese Dictionary

4. 在这个问题上，还是老师说的话算数。

   zài zhè​ge wèn​tí shàng, hái​shi lǎo​shī shuō de huà suàn​shù.

   On this matter, the teacher's word is final.

   Source: Dong Chinese Dictionary