newbe help with formula

[DR, Bob]

I need a easy way to count the following cells with numbers less then 10.

columns c to h, rows 2 to 20, 30 to 40 & 50 to 60 in each column. The next 5
sheets I need to do the same thing but the rows are different on each sheet.

I was going to use
=(COUNTIF(c2:c20,"<10"))+(COUNTIF(c30:c40,"<10"))+(COUNTIF(c50:c60,"<10"))+.
.... and so on until I have all the rows and columns covered but the formula
will get very long.

Is there a shorter formula I could use to save from using this very long
formula???

Thanks