Hello Daniel,
I would have to agree with malwaredpc, but being a person who lives in a relatively remote area myself I can understand you wanting to try to keep your computer going a little longer until you are able to organize the right replacement parts.
There is a line you can enable in your grub configuration file which will allow you to have Gnu-Grub pass information to the linux kernel on boot up about which sectors of memory you want the kernel to avoid.
Here are a couple of links:
https://www.gnu.org/software/grub/manual/html_node/badram.html — Gnu Grub Manual on Bad Ram
https://help.ubuntu.com/community/BadRAM – BadRAM - Ubuntu Communuty Docs
You will need to run memtest86+ first from your grub menu when you are booting up to find out what the bad sectors are. You will find that in your Grub Menu when you boot your computer up if you have more than one operating system in the computer. If your Grub menu doesn’t show, try tapping your ‘esc’ key during boot-up, that should bring it up. Then press a down-arrow key to select memtest86+.
To set up Grub to tell the Linux kernel in Ubuntu MATE which are your bad ram sectors you need to boot Ubuntu MATE, (somehow if you can get it running with the faulty memory), and open your grub settings file,
gksudo pluma /etc/default/grubedited by herman in response to malwaredpc’s advice in a later post.
This is what mine looks like, yours doesn’t have to be exactly the same as mine
Just look for the line that looks like this: "#GRUB_BADRAM=“0x01234567,0xfefefefe,0x89abcdef,0xefefefef”.
You will be wanting to delete the ‘comment’ (looks like: ‘#’ ), from the start of that line to enable that feature and you will need to replace the example sector numbers given there with your own actual results reported by memtest86+.
[code]# If you change this file, run ‘update-grub’ afterwards to update
/boot/grub/grub.cfg.
For full documentation of the options in this file, see:
info -f grub -n ‘Simple configuration’
GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=lsb_release -i -s 2> /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash”
GRUB_CMDLINE_LINUX=“elevator=noop”
Uncomment to enable BadRAM filtering, modify to suit your needs
This works with Linux (no patch required) and with any kernel that obtains
the memory map information from GRUB (GNU Mach, kernel of FreeBSD …)
#GRUB_BADRAM=“0x01234567,0xfefefefe,0x89abcdef,0xefefefef”
Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console
The resolution used on graphical terminal
note that you can use only modes which your graphic card supports via VBE
you can see them in real GRUB with the command `vbeinfo’
#GRUB_GFXMODE=640x480
Uncomment if you don’t want GRUB to pass “root=UUID=xxx” parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true
Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY=“true”
Uncomment to get a beep at grub start
#GRUB_INIT_TUNE=“480 440 1”[/code]
To make the changes in your grub configuration file effective, you will need to run one more command,
sudo update-grubNow the next time you reboot your Ubuntu MATE should be avoiding those sectors of bad ram.
I have never needed to try this out myself so I’m just going by what I have been reading and hoping I’m right. I have a reasonable amount of experience with Gnu-Linux in general and with Gnu-Grub. This is what I would try first anyway. I hope it works out right for you on the first try.
You didn’t mention if you’re an experienced Gnu-Linux user new to Ubuntu MATE, or if you’re new from Windows and you need step-by-step instructions so I gave you half and half. If there are things you need explained in more detail please ask and I’ll elaborate even more. 
Good luck with it,
Regards from Herman