The underlying math for this is as follows. A number have to split will be split into repeats of two numbers. The smaller number is given by:
=QUOTIENT(NUMBER_HAVE_TO_SPLIT,SPLIT_BY_PARTS)
And the larger number is given by:
=QUOTIENT(NUMBER_HAVE_TO_SPLIT,SPLIT_BY_PARTS)+1
FYI the QUOTIENT worksheet function does integer division, e.g, QUOTIENT(13,4)=3.
The number of times the larger number is repeated is given by:
=MOD(NUMBER_HAVE_TO_SPLIT,SPLIT_BY_PARTS)
And the number of times the smaller number is repeated is given by:
=SPLIT_BY_PARTS - MOD(NUMBER_HAVE_TO_SPLIT,SPLIT_BY_PARTS)
The remaining task is to return the results in the formats you suggest. To get the comma-delimited format 3,4,4:
- Convert both smaller numbers and larger numbers to text using TEXT(number,0)
- Prepend each with a comma to give the strings,3 and,4
- Use the REPT function to repeat each the appropriate number of times to give,3 and,4,4
- Concatenate these two strings and use SUBSTITUTE to remove the first comma
A somewhat messy formula to accomplish the above is:
=SUBSTITUTE(REPT(","&TEXT(QUOTIENT(A2,B2),"0"),B2-MOD(A2,B2))&REPT(","&TEXT(QUOTIENT(A2,B2)+1,"0"),MOD(A2,B2)),",","",1)
where NUMBER_HAVE_TO_SPLIT and SPLIT_BY_PARTS are in A2 and B2, respectively.
A formula to generate the 3=1 and 4=2 format is
=TEXT(QUOTIENT(A2,B2),0)&"="&TEXT(B2-MOD(A2,B2),"0")&IF(MOD(A2,B2)>0," and "&TEXT(QUOTIENT(A2,B2)+1,0)&"="&TEXT(MOD(A2,B2),"0"),"")