# Alternatives for finding n significant figures

Note

• The following formula calculates N significant figures

123456789

• TEXT(IF(A1<0,"-","")&LEFT(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00"),3+1)*10^FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1),(""&(IF(OR(AND(FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1)+1=3,RIGHT(LEFT(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00"),3+1)*10^FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1),1)="0"),LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00"))<=3-1),"0.","#")&REPT("0",IF(3-1-(FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1))>0,3-1-(FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1)),0)))))

• don’t work

• under investigation

123456789

ROUND(a2,3-(1+INT(LOG10(ABS(a2)))))

123800210

ROUND(a3,3-(1+INT(LOG10(ABS(a3)))))

13.123

ROUND(a4,3-(1+INT(LOG10(ABS(a4)))))

with a format, “#.#”

13

ROUND(a5,3-(1+INT(LOG10(ABS(a5)))))

with a format, “#.#”

table2

123456789

TEXT(IF(A1<0,"-","")&LEFT(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00"),3+1)*10^FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1),(""&(IF(OR(AND(FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1)+1=3,
RIGHT(TEXT(LEFT(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00"),3+1)*10^FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1), "#."),1)
="0"),LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00"))<=3-1),"0.","#")&REPT("0",IF(3-1-(FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1))>0,3-1-(FLOOR(LOG10(TEXT(ABS(A1),"0."&REPT("0",3-1)&"E+00")),1)),0)))))

First argument of RIGHT function must be String.

So, inserted TEXT(val, “#”) after RIGHT function.