For Debian users, TuxMath 1.5.4 is now in the Sid/Unstable branch, and TuxMath 1.5.3 has migrated into Testing. On the TuxType side, 1.5.15 was recently uploaded to Unstable.
(thanks to Holger Levsen, Debian maintainer for the TuxMath and TuxType packages).
If you use Debian or a Debian derivative (e.g. Ubuntu), you can use apt to install these packages from the Debian archives rather than building from the tar.gz files here.
Cheers,
David Bruce