Translate numbers to French
Excel, 153 149 Bytes

=IF(OR(A1&lt;17,A1&gt;99,AND(A1&gt;19,A1&lt;70)),A1,IF(A1&lt;20,"10+"&amp;A1-10,IF(A1&lt;80,"60","4*20")&amp;IF(A1=80,,IF(MOD(A1,20)&gt;16,"+10+"&amp;MOD(A1,20)-10,"+"&amp;MOD(A1,20)))))


I'm sure this could be better, I struggled to find an efficient way to account for #80.

edit: Consolidated the 'Normal' cases better to save 4 bytes.  #80 still sucks.

Can't find a specific answer on here, not sure the rules of code-golf tbh.  Can I use multiple cells in Excel, and add the byte count of each?

ie. For an input in cell A1

A2: 11 Bytes

=MOD(A1,20)


A3 (result): 125 Bytes

=IF(OR(A1&lt;17,A1&gt;99,AND(A1&gt;19,A1&lt;70)),A1,IF(A1&lt;20,"10+"&amp;A1-10,IF(A1&lt;80,"60","4*20")&amp;IF(A1=80,,IF(A2&gt;16,"+10+"&amp;A2-10,"+"&amp;A2))))


For a total of 136?