Your note isn't showing any additional storage? What does it say when you go to Menu > Settings > Device > Storage . If there is an option for SD card and it shows the space then you should be all good.

I have done what you have elaborated on but it didn't work. I have removed the battery, inserted the memory card, put back the battery, turned on the telephone and it doesn't show any thing (to reformat or any other instruction on the screen, only the front page with all the icons. So what have I done wrong?
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Insert a memory card

To store additional multimedia files, you must insert a memory card. Your device accepts microSD or
microSDHC memory cards with maximum capacities of 32 GB (depending on memory card manufacturer and type). Samsung uses approved industry standards for memory cards, but some brands may not be fully compatible with your device. Using an incompatible memory card may damage your device or the memory card and can corrupt data stored on the card.

• Your device supports only the FAT file structure for memory cards. If you insert a card formatted with a different file structure, your device will ask you to reformat the memory card.
• Frequent writing and erasing of data will shorten the lifespan of your memory cards.
• When you insert a memory card into your device, the memory card’s file directory will appear in the external_sd folder under the internal memory.

Remove the back cover and battery. Insert a memory card with the gold-colored contacts facing downwards. Push the memory card into the memory card slot until it locks in place. Replace the battery and back cover.

Remove the memory card

Before removing a memory card, first unmount it for safe removal. In Idle mode, select Applications - Settings - Storage - Unmount SD card - OK. Remove the back cover and battery. Push the memory card gently until it disengages from the device. Remove the memory card. Replace the battery and back cover.

Format the memory card

Formatting your memory card on a PC may cause incompatibilities with your device. Format the memory card only on the device. In Idle mode, select Applications - Settings - Storage - Unmount SD card - OK - Format SD card - Format SD card - Erase everything. Before formatting the memory card, remember to make backup copies of all important data stored on your device. The manufacturer’s warranty does not cover loss of data resulting from user actions.