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With a 1:3:6 mix for 100 cubic meter of concrete you would need 420 x 50kg bags of cement, 56 cubic meters of fine aggregate (sand and gravel passing through a 5mm sieve) and 79 cubic metres of coarse aggregate (gravel retained by a 5mm sieve).

For 10 square meters of concrete block wall, you would need 110 blocks, assuming a mortar bed depth of 10mm and with a mix of 1:5 cement: sand and 10% wastage you would need 1.225 cubic metres of mortar, which would require 0.245 cubic metres of cement and 1.225 cubic metres of sand (the cement sits in the spaces between sand grains and so does not bulk up the sand volume). 245 litres of cement is about 7.5 bags of cement (1 x 50kg bag is 33 litres). If your mortar bed is thicker, increase the quantities in proportion - 12 mm bed would increase cement and sand by 20%.

I have to admit that the cement quantities for concrete are direct from a table in Engineering in Emergencies and so should be accurate. I have done the calcs for mortar from first principles (11 blocks/square metre is a known), bed depth seems ok but could be increased as a factor of safety. If you can get some plasticiser or hydrated lime (not agricultural) to add to the mortar it would be much more workable - use a cement: lime: mortar mix of 1:1:5 so same amount of lime as cement. Make sure the sand is finer for the mortar (sand and not fine aggregate) than the concrete and well washed.

If you need more come back and we'll see if we can give you more details. The RedR book Engineering in Emergencies gives good construction detailing for both concrete and mortar.

Regards, Toby Gould