with worksheets("sheet1")
    on error resume next
    set rng = .range("B6:H6").specialcells(xlcelltypeformulas, xlerrors)
    if not rng is nothing then
        rng.formular1c1 = "=average(r5c, r7c)"
    end if
    set rng = .range("B10:H11").specialcells(xlcelltypeformulas, xlerrors)
    if not rng is nothing then
        rng.formular1c1 = "=average(r9c, r12c)"
    end if
end with