In the songs (popular), time signatures that we often encounter is a sign that measures of 4/4. Rhythm Rock'n Roll, Bossanova, Cha Cha, Rumba, Samba, Jive, etc. are some examples of the marked rhythm measures of 4/4.
Mathematically equal to: ? +? +? +? = ¼ + ¼
In the second bars are half tones: ½ = ¼ + ¼