Meaning of bù dào:
不到
not to arrive; not reaching
Huǒchē búdào shí diǎn jiù dào le.
火车不到十点就到了。
The train arrived before ten o'clock.
Zhè cì huìyì wǒmen yòngle bù dào yīgè xiǎoshí.
这次会议我们用了不到一个小时。
We used less than an hour for this meeting.
insufficient
Tā de tǐzhòng hái bùdào wǔshí gōngjīn.
他的体重还不到五十公斤。
His weight is still insufficient to reach fifty kilograms.
less than
Tā pǎo le bù dào wǔ gōnglǐ jiù lèi le.
他跑了不到五公里就累了。
He got tired after running less than five kilometers.