if you want to use them as text and not as a calculation for the little line with a dot above and below Type Alt+0247 (Hold down the Alt key and type 0247 using the number pad, not the ones at top of keyboard)
It is in character map in 'Lucida Console' 2nd column 10th one down if you just want to copy and paste it.
multiplication sign, × is Alt+0215. You can also use an asterisk, * or an 'x'
Sorry for the triple posting but I have just discovered that if you open 'Character Map' and then click on the down arrow in the 'Group by:' box and choose 'Unicode Subrange' you get a pop up box that includes 'Mathematical Operaters' and then you don't have to search through the whole character set for each font as it finds and shows just the maths ones. You can also then just change the font from top 'Font' drop down menu and it shows the maths symbols for whatever font you choose.