On Pesukei Dezimrah: Four From The Artscroll Siddur

1. Pesukei DeZimrah, according to the AriZal, means The Verses of Pruning: clearing away our distractions before we recite Shemah and Shemoneh Esrei.

2.. Baruch She'Amar has 87 words in it, corresponding to the golden - paz - nature of this holy prayer.

3. The first part of Hodu consists of 29 lines.  The first fifteen were sung in the Mishakan when the morning Tamid was offered.  The last 14 were sung when the afternoon Tamid was offered

3. Ashkenazim focus on the fact that Hodu is sentences of praise of G-d.  Sefardim focus on the fact that Hodu, in part, was recited when the Korban Tamid was offered.  This is why Ashkenazim say it after Baruch She'Amar, as part of Pesukei DeZimrah.  And this is why Sefardim say it before Baruch She'Amar, along with Korbanot,

4. Yishtabach has fifteen words of praise in its first half and fifteen words following the introductory words (Baruch atah Hashem) to the ending bracha. "This number alludes to the fifteen Songs of Ascents (Tehillim 120-134) composed by David. Also, fifteen is the number of the Divine Name, yud heh, the letters used to create heaven and earth; thus it signifies that everything is G-d's.