All rows carry one mathematical operator (to simplify only 4 basic maths operators which are +, -, * and / ). Concat all cells to the left of operator and perform mathematical operation on concatenation of all cells to the right of operator. Ex. Row 2 – Left of operator concatenation: 1354 Right of operator concatenation: 15205 Mathematical operation for + = 1354 + 15205 = 16559 Row 3 = 191031019/9 = 21225668.78
📌 Challenge Details and Links
ExcelBI Excel Challenge Number: 472
Challenge Difficulty: ⭐️
📥Download Sample File
📥Link to the solutions on LinkedIn
Solving the challenge of Evaluate Concatenated Math Rows with Power Query
Power Query solution 1 for Evaluate Concatenated Math Rows, proposed by Kris Jaganah:
let
Source = Excel.CurrentWorkbook(){[Name = "Table1"]}[Content],
Ans = Table.AddColumn(
Source,
"Answer expected",
each Expression.Evaluate(Text.Combine(List.Transform(Record.ToList(_), each Text.From(_))))
)
in
AnsPower Query solution 2 for Evaluate Concatenated Math Rows, proposed by Aditya Kumar Darak 🇮🇳:
let
Source = Excel.CurrentWorkbook(){[Name = "data"]}[Content],
Return = Table.TransformRows(
Source,
each Expression.Evaluate(Text.Combine(List.Transform(Record.ToList(_), Text.From)))
)
in
ReturnPower Query solution 3 for Evaluate Concatenated Math Rows, proposed by Alejandro Simón 🇵🇦 🇪🇸:
let
Source = Excel.CurrentWorkbook(){[Name = "Table1"]}[Content],
Sol = Table.AddColumn(
Source,
"Answer",
each
let
a = Record.ToList(_),
b = List.Transform(
Text.SplitAny(Text.Combine(List.Transform(a, Text.From)), "+-*/"),
Number.From
),
c =
if List.Contains(a, "+") then
b{0} + b{1}
else if List.Contains(a, "-") then
b{0} - b{1}
else if List.Contains(a, "/") then
b{0} / b{1}
else
b{0} * b{1}
in
c
)[[Answer]]
in
SolPower Query solution 4 for Evaluate Concatenated Math Rows, proposed by Alejandro Simón 🇵🇦 🇪🇸:
let
Source = Excel.CurrentWorkbook(){[Name = "Table1"]}[Content],
Sol = Table.AddColumn(
Source,
"Answer",
each Expression.Evaluate(Text.Combine(List.Transform(Record.ToList(_), Text.From)))
)[[Answer]]
in
SolPower Query solution 5 for Evaluate Concatenated Math Rows, proposed by Brian Julius:
let
Source = Excel.CurrentWorkbook(){[Name = "Table1"]}[Content],
ColList = Table.ColumnNames(Source),
TextList = List.Repeat({Text.Type}, List.Count(ColList)),
ReTypeAll = Table.TransformColumnTypes(Source, List.Zip({ColList, TextList})),
Merge = Table.CombineColumns(
ReTypeAll,
Table.ColumnNames(Source),
Combiner.CombineTextByDelimiter(""),
"Exp"
),
Evaluate = Table.RemoveColumns(
Table.AddColumn(Merge, "Answer", each Expression.Evaluate([Exp])),
"Exp"
)
in
EvaluatePower Query solution 6 for Evaluate Concatenated Math Rows, proposed by Abdallah Ally:
let
a = Excel.CurrentWorkbook(){[Name = "Table1"]}[Content],
b = Table.AddColumn(
a,
"Results",
each Text.Combine(List.Transform(Record.ToList(_), Text.From), "")
),
c = List.Transform(b[Results], Expression.Evaluate)
in
cPower Query solution 7 for Evaluate Concatenated Math Rows, proposed by Ramiro Ayala Chávez:
let
S = Excel.CurrentWorkbook(){[Name = "Table1"]}[Content],
a = Table.TransformColumnTypes(
S,
{
{"N1", type text},
{"N2", type text},
{"N3", type text},
{"N4", type text},
{"N5", type text},
{"N6", type text},
{"N7", type text}
}
),
Sol = Table.AddColumn(
a,
"Answer Expected",
each Expression.Evaluate([N1] & [N2] & [N3] & [N4] & [N5] & [N6] & [N7])
)
in
SolPower Query solution 8 for Evaluate Concatenated Math Rows, proposed by Venkata Rajesh:
let
Source = Data,
Output = Table.AddColumn(
Source,
"Expected",
each [
x = Record.ToList(_),
y = Text.Combine(List.Transform(x, Text.From), ""),
z = Expression.Evaluate(y)
][z]
)[[Expected]]
in
OutputPower Query solution 9 for Evaluate Concatenated Math Rows, proposed by Kalyan Kumar Reddy Kethireddy:
let
Source = Table.FromRows(
Json.Document(
Binary.Decompress(
Binary.FromText(
"bU9BDoAgDPsLR4XIFAXfYvj/N2w3RmLiocvadWU8T5AjxHACBVgBIdmzqj3CcFMkP7xRaQNuc+y+pmFkieRikb8QLWWESFOLrxWfVVtHqWq4fKBPreOl01QayozmYGEDNDtYrxD/2myS5Uek09HmUUD+oPcX",
BinaryEncoding.Base64
),
Compression.Deflate
)
),
let
_t = ((type nullable text) meta [Serialized.Text = true])
in
type table [N1 = _t, N2 = _t, N3 = _t, N4 = _t, N5 = _t, N6 = _t, N7 = _t]
),
ExtractColumnNames = Table.ColumnNames(Source),
CombineAllColumns = Table.CombineColumns(
Source,
ExtractColumnNames,
Combiner.CombineTextByDelimiter("", QuoteStyle.None),
"Answer Expected"
),
Evaluate = Table.TransformColumns(
CombineAllColumns,
{"Answer Expected", each Expression.Evaluate(_)}
)
in
EvaluateSolving the challenge of Evaluate Concatenated Math Rows with Excel
Excel solution 1 for Evaluate Concatenated Math Rows, proposed by Bo Rydobon 🇹🇭:
=LAMBDA(
x,
EVALUATE(
CONCAT(
x
)
)
)
Then
=BYROW(
A2:G10,
Eval
)Excel solution 2 for Evaluate Concatenated Math Rows, proposed by Bo Rydobon 🇹🇭:
=BYROW(
A2:G10,
LAMBDA(
a,
LET(
n,
TEXTSPLIT(
CONCAT(
a
),
{"+",
"-",
"*",
"/"}
),
m,
IF(
OR(
a={"+";"*"}
),
1,
{1,
-1}
),
IF(
OR(
a={"+";"-"}
),
SUM(
n*m
),
PRODUCT(
n^m
)
)
)
)
)
=BYROW(
A2:G10,
LAMBDA(
a,
LET(
n,
REGEXEXTRACT(
CONCAT(
a
),
"d+",
1
),
m,
IF(
OR(
a={"+";"*"}
),
1,
{1;-1}
),
IF(
OR(
a={"+";"-"}
),
SUM(
n*m
),
PRODUCT(
n^m
)
)
)
)
)Excel solution 3 for Evaluate Concatenated Math Rows, proposed by Rick Rothstein:
=BYROW(
A2:G10,
LAMBDA(
r,
LET(
a,
{"+",
"-",
"*",
"/"},
t,
TEXTSPLIT(
CONCAT(
r
),
,
a
),
f,
TAKE(
t,
1
),
s,
TAKE(
t,
-1
),
CHOOSE(
TOCOL(
XMATCH(
r,
a
),
3
),
f+s,
f-s,
f*s,
f/s
)
)
)
)Excel solution 4 for Evaluate Concatenated Math Rows, proposed by John V.:
=LAMBDA(
x;EVALUATE(
CONCAT(
x
)
)
)
And then,
use this formula:
=BYROW(
A2:G10;e
)
✅=BYROW(
A2:G10,
LAMBDA(
r,
LET(
i,
CONCAT(
r
),
s,
{"-";"*";"/";"+"},
a,
TEXTBEFORE(
i,
s
),
b,
TEXTAFTER(
i,
s
),
CHOOSE(
MATCH(
FILTER(
r,
r>""
),
s
),
a-b,
a*b,
a/b,
a+b
)
)
)
)Excel solution 5 for Evaluate Concatenated Math Rows, proposed by محمد حلمي:
=BYROW(
A2:G10,
LAMBDA(
a,
LET(
i,
XMATCH(
1,
IFERROR(
-a,
1
)
),
v,
CONCAT(
TAKE(
a,
,
i-1
)
),
c,
CONCAT(
DROP(
a,
,
i
)
),
SWITCH(
INDEX(
a,
i
),
"+",
v+c,
"/",
v/c,
"*",
v*c,
v-c
)
)
)
)Excel solution 6 for Evaluate Concatenated Math Rows, proposed by محمد حلمي:
=BYROW(
A2:G10,
LAMBDA(
a,
LET(
e,
CODE(
a
)-41,
i,
XMATCH(
1,
e,
1
),
v,
CONCAT(
TAKE(
a,
,
i-1
)
),
c,
CONCAT(
DROP(
a,
,
i
)
),
CHOOSE(
INDEX(
e,
i
),
v*c,
v+c,
,
v-c,
,
v/c
)
)
)
)Excel solution 7 for Evaluate Concatenated Math Rows, proposed by Kris Jaganah:
=BYROW(
A2:G10,
LAMBDA(
x,
LET(
a,
CONCAT(
x
),
b,
REGEXEXTRACT(
a,
"[*/+-]"
),
c,
--TEXTSPLIT(
a,
,
b
),
d,
TAKE(
c,
1
),
e,
DROP(
c,
1
),
SWITCH(
b,
"+",
d+e,
"/",
d/e,
"-",
d-e,
"*",
d*e
)
)
)
)Excel solution 8 for Evaluate Concatenated Math Rows, proposed by Julian Poeltl:
=BYROW(
A2:G10,
LAMBDA(
A,
LET(
C,
CONCAT(
A
),
P,
TEXTSPLIT(
C,
,
"+"
),
M,
TEXTSPLIT(
C,
,
"-"
),
Mu,
TEXTSPLIT(
C,
,
"*"
),
D,
TEXTSPLIT(
C,
,
"/"
),
IFERROR(
INDEX(
P,
1
)+INDEX(
P,
2
),
IFERROR(
INDEX(
M,
1
)-INDEX(
M,
2
),
IFERROR(
INDEX(
Mu,
1
)*INDEX(
Mu,
2
),
INDEX(
D,
1
)/INDEX(
D,
2
)
)
)
)
)
)
)Excel solution 9 for Evaluate Concatenated Math Rows, proposed by Julian Poeltl:
=BYROW(
A2:G10,
LAMBDA(
A,
LET(
C,
CONCAT(
A
),
SP,
TEXTSPLIT(
C,
{"-",
"+",
"*",
"/"}
),
A,
INDEX(
SP,
1
),
B,
INDEX(
SP,
2
),
SWITCH(
CONCAT(
TEXTSPLIT(
C,
SEQUENCE(
10,
,
0
)
)
),
"-",
A-B,
"+",
A+B,
"*",
A*B,
"/",
A/B
)
)
)
)Excel solution 10 for Evaluate Concatenated Math Rows, proposed by Timothée BLIOT:
=LET(
T,
BYROW(
A2:G10,
LAMBDA(
x,
CONCAT(
x
)
)
),
V,
{"+",
"-",
"*",
"/"},
MAP(
T,
LAMBDA(
x,
LET(
W,
FILTER(
V,
ISNUMBER(
FIND(
V,
x
)
)
),
N,
--TEXTSPLIT(
x,
,
V
),
A,
INDEX(
N,
1
),
B,
& INDEX(
N,
2
),
SWITCH(
W,
"+",
A+B,
"-",
A-B,
"*",
A*B,
"/",
A/B
)
)
)
)
)Excel solution 11 for Evaluate Concatenated Math Rows, proposed by Hussein SATOUR:
=BYROW(
A2:G10,
LAMBDA(
x,
LET(
v,
REGEXEXTRACT(
CONCAT(
x
),
"(d+)|([*/+/-//])|(d+)",
1
),
a,
INDEX(
v,
1
),
b,
INDEX(
v,
3
),
SWITCH(
INDEX(
v,
2
),
"+",
a+b,
"/",
a/b,
"*",
a*b,
a-b
)
)
)
)Excel solution 12 for Evaluate Concatenated Math Rows, proposed by Oscar Mendez Roca Farell:
=BYROW(A2:G10,
LAMBDA(r,
LET(c,
CONCAT(
r
),
m,
{1,
-1},
w,
"-+/*",
f,
TOCOL(
FIND(
r,
w
),
2
),
n,
TEXTSPLIT(
c,
MID(
w,
f,
1
)
),
IF(f<3,
SUM(n*m^(f-2)),
PRODUCT(n^(m^(4-f)))))))Excel solution 13 for Evaluate Concatenated Math Rows, proposed by Sunny Baggu:
=LET(
s,
BYROW(
A2:G10,
LAMBDA(
x,
CONCAT(
x
)
)
),
MAP(
s,
LAMBDA(
t,
LET(
ts,
TEXTSPLIT(
t,
,
{"+"; "-"; "*"; "/"}
),
a,
TAKE(
ts,
1
),
b,
TAKE(
ts,
-1
),
c,
FILTER(
SEQUENCE(
4
),
ISNUMBER(
FIND(
{"+"; "-"; "*"; "/"},
t
)
)
),
IFS(
c = 1,
a + b,
c = 2,
a - b,
c = 3,
a * b,
1,
a / b
)
)
)
)
)Excel solution 14 for Evaluate Concatenated Math Rows, proposed by Abdallah Ally:
=BYROW(
A2:G10,
LAMBDA(
x,
LET(
a,
CONCAT(
x
),
b,
{"+",
"-",
"*",
"/"},
c,
TEXTBEFORE(
a,
b
),
d,
TEXTAFTER(
a,
b
),
f,
LAMBDA(
x,
y,
NOT(
ISERROR(
FIND(
x,
y
)
)
)
),
IFS(
f(
"+",
a
),
c+d,
f(
"-",
a
),
c-d,
f(
"*",
a
),
c*d,
f(
"/",
a
),
c/d
)
)
)
)Excel solution 15 for Evaluate Concatenated Math Rows, proposed by 🇵🇪 Ned Navarrete C.:
=BYROW(
A2:G10,
LAMBDA(
r,
LET(
e,
LAMBDA(
i,
x,
y,
CHOOSE(
XMATCH(
i,
{"+",
"-",
"*",
"/"}
),
x+y,
x-y,
x*y,
x/y
)
),
t,
CONCAT(
r
),
o,
FILTER(
r,
r>""
),
e(
o,
TEXTBEFORE(
t,
o
),
TEXTAFTER(
t,
o
)
)
)
)
)Excel solution 16 for Evaluate Concatenated Math Rows, proposed by Asheesh Pahwa:
=BYROW(
A2:G10,
LAMBDA(
x,
LET(
mo,
{"+",
"-",
"*",
"/"},
c,
CONCAT(
x
),
t,
TEXTSPLIT(
c,
mo
),
f,
--TAKE(
t,
,
1
),
l,
--TAKE(
t,
,
-1
),
xm,
XMATCH(
x,
mo
),
tc,
TOCOL(
xm,
3
),
ch,
CHOOSE(
tc,
f+l,
f-l,
f*l,
f/l
),
ch
)
)
)Excel solution 17 for Evaluate Concatenated Math Rows, proposed by Meganathan Elumalai:
=LET(
a,
{"+",
"-",
"/",
"*"},
Rng,
A2:G2,
Opr,
MATCH(
FALSE,
ISNUMBER(
Rng
),
0
),
fset,
CONCAT(
INDEX(
Rng,
ROW(
INDIRECT(
"1:"&Opr-1
)
)
)
),
sset,
CONCAT(
INDEX(
Rng,
ROW(
INDIRECT(
Opr+1&":"&COLUMNS(
Rng
)
)
)
)
),
CHOOSE(
MATCH(
"~"&INDEX(
Rng,
Opr
),
a,
0
),
fset+sset,
fset-sset,
fset/sset,
fset*sset
)
)Excel solution 18 for Evaluate Concatenated Math Rows, proposed by Bilal Mahmoud kh.:
LET(
a,
BYROW(
A2:G10,
LAMBDA(
x,
TEXTSPLIT(
CONCAT(
x
),
CHAR(
SEQUENCE(
10,
,
48,
1
)
),
,
TRUE()
)
)
),
b,
--BYROW(
A2:G10,
LAMBDA(
x,
TAKE(
TEXTSPLIT(
CONCAT(
x
),
{"+",
"-",
"*",
"/"},
,
TRUE()
),
,
1
)
)
),
c,
--BYROW(
A2:G10,
LAMBDA(
x,
DROP(
TEXTSPLIT(
CONCAT(
x
),
{"+",
"-",
"*",
"/"},
,
TRUE()
),
,
1
)
)
),
res,
SWITCH(
a,
"+",
b+c,
"-",
b-c,
"*",
b*c,
"/",
b/c
),
res
)Excel solution 19 for Evaluate Concatenated Math Rows, proposed by Milan Shrimali:
=BYROW(
A1:G10,
LAMBDA(
y,
LET(
opt,
BYROW(
y,
LAMBDA(
x,
UNIQUE(
IF(
ISTEXT(
x
),
x,
""
),
1,
1
)
)
),
join,
TEXTJOIN(
"",
,
y
),
BF,
TEXTBEFORE(
join,
opt
),
AF,
TEXTAFTER(
join,
opt
),
IFS(
opt="+",
BF+AF,
opt="/",
BF/AF,
opt="-",
BF-AF,
opt="*",
BF*AF
)
)
)
)Excel solution 20 for Evaluate Concatenated Math Rows, proposed by Edwin Tisnado:
=BYROW(
A2:G10,
LAMBDA(
x,
LET(
b,
{"+",
"-",
"*",
"/"},
c,
{1,
-1},
t,
CONCAT(
x
),
n,
--TEXTSPLIT(
t,
b
),
i,
XMATCH(
1,
FIND(
b,
t
),
1
),
IFS(
i=1,
SUM(
n
),
i=2,
SUM(
n*c
),
i=3,
PRODUCT(
n
),
i=4,
PRODUCT(
n^c
)
)
)
)
)Excel solution 21 for Evaluate Concatenated Math Rows, proposed by Anup Kumar:
=BYROW(
A2:G10,
LAMBDA(
x,
LET(
lst,
{"+",
"-",
"/",
"*"},
str,
TEXTJOIN(
"",
1,
x
),
a,
--TEXTBEFORE(
str,
lst
),
b,
--TEXTAFTER(
str,
lst
),
opr,
XMATCH(
MID(
str,
LEN(
a
)+1,
1
),
lst
),
SWITCH(
opr,
1,
a+b,
2,
a-b,
3,
a/b,
4,
a*b
)
)
)
)Excel solution 22 for Evaluate Concatenated Math Rows, proposed by Diarmuid Early:
=LAMBDA(
x,
EVALUATE(
x
)
)
Then this solves it:
=BYROW(
A2:G10,
LAMBDA(
rw,
evalFunc(
CONCAT(
rw
)
)
)
)
EVALUATE turns a string into a formula (a bit like INDIRECT converts a string into a range reference)Excel solution 23 for Evaluate Concatenated Math Rows, proposed by Burhan Cesur:
=BYROW(
A2:G10,
LAMBDA(
x,
WEBSERVICE(
"http://api.mathjs.org/v4/?expr="&ENCODEURL(
CONCAT(
x
)
)
)
)
)Excel solution 24 for Evaluate Concatenated Math Rows, proposed by Burhan Cesur:
=LET(
s,
{"+",
"-",
"*",
"/"},
a,
BYROW(
A2:G10,
LAMBDA(
x,
CONCAT(
x
)
)
),
b,
--TEXTBEFORE(
a,
s
),
c,
--TEXTAFTER(
a,
s
),
f,
LAMBDA(
x,
ISNUMBER(
SEARCH(
x,
a
)
)
),
IFS(
f(
"+"
),
b+c,
f(
"-"
),
b-c,
f(
"/"
),
b/c,
f(
"*"
),
b*c
)
)Excel solution 25 for Evaluate Concatenated Math Rows, proposed by Bevon Clarke:
=BYROW(
A2:G10;
LAMBDA(
x;
LET(
cha;
{"+";
"-";
"*";
"/"};
nbf;
TAKE(
VALUE(
TEXTSPLIT(
CONCAT(
x
);
cha
)
);
;
1
);
nba;
TAKE(
VALUE(
TEXTSPLIT(
CONCAT(
x
);
cha
)
);
;
-1
);
mo;
CONCAT(
IFNA(
XLOOKUP(
cha;
x;
x
);
""
)
);
IFS(
mo="+";
nbf+nba;
mo="-";
nbf-nba;
mo="*";
nbf*nba;
mo="/";
nbf/nba
)
)
)
)Excel solution 26 for Evaluate Concatenated Math Rows, proposed by Caroline Blake:
=BYROW(
A2:G10,
LAMBDA(
a,
LET(
b,
IF(
ISNUMBER(
a
),
a,
":"
),
c,
FILTER(
a,
b=":"
),
_n,
LAMBDA(
x,
CHOOSEROWS(
VALUE(
TEXTSPLIT(
CONCAT(
b
),
,
":"
)
),
x
)
),
IF(
c="+",
_n(
1
)+_n(
2
),
IF(
c="-",
_n(
1
)-_n(
2
),
& IF(
c="/",
_n(
1
)/_n(
2
),
_n(
1
)*_n(
2
)
)
)
)
)
)
)Solving the challenge of Evaluate Concatenated Math Rows with Python
Python solution 1 for Evaluate Concatenated Math Rows, proposed by Konrad Gryczan, PhD:
import pandas as pd
input = pd.read_excel("472 Operator in a grid.xlsx", usecols="A:G", nrows = 9)
test = pd.read_excel("472 Operator in a grid.xlsx", usecols="I", nrows = 9)
pattern = r'^(d+)(D+)(d+)$'
def evaluate_expression(n1, op, n2):
n1 = float(n1)
n2 = float(n2)
if op == "+":
return n1 + n2
elif op == "-":
return n1 - n2
elif op == "*":
return n1 * n2
elif op == "/":
return n1 / n2
input = input.astype(str)
result = input.apply(lambda row: "".join(row), axis=1)
result = result.str.extract(pattern)
result.columns = ["n1", "op", "n2"]
result["Answer Expected"] = result.apply(lambda row: evaluate_expression(row["n1"], row["op"], row["n2"]), axis=1)
print(result["Answer Expected"].equals(test["Answer Expected"])) # True
Solving the challenge of Evaluate Concatenated Math Rows with Python in Excel
Python in Excel solution 1 for Evaluate Concatenated Math Rows, proposed by Abdallah Ally:
import pandas as pd
pd.set_option('display.float_format', '{:.4f}'.format)
file_path = 'Excel_Challenge_472 - Operator in a grid.xlsx'
df = pd.read_excel(file_path, usecols='A:I').dropna(axis=1)
# Perform data wrangling
df['My Answer'] = df.apply(lambda x: eval(''.join(x[:-1].map(str))), axis=1)
df['Check'] = df['Answer Expected'] == df['My Answer']
df
Solving the challenge of Evaluate Concatenated Math Rows with R
R solution 1 for Evaluate Concatenated Math Rows, proposed by Konrad Gryczan, PhD:
I found some time :D
library(tidyverse)
library(readxl)
library(rlang)
input = read_excel("Excel/472 Operator in a grid.xlsx", range = "A1:G10")
test = read_excel("Excel/472 Operator in a grid.xlsx", range = "I1:I10")
result2 = input %>%
unite("result", 1:7, sep = "") %>%
mutate(`Answer Expected` = map_dbl(result, ~ eval(parse_expr(.x))))
identical(result2$`Answer Expected`, test$`Answer Expected`)
#> [1] TRUE
R solution 2 for Evaluate Concatenated Math Rows, proposed by Konrad Gryczan, PhD:
library(tidyverse)
library(readxl)
library(rebus)
input = read_excel("Excel/472 Operator in a grid.xlsx", range = "A1:G10")
test = read_excel("Excel/472 Operator in a grid.xlsx", range = "I1:I10")
pattern = START %R% capture(one_or_more(DGT)) %R% capture(NOT_DGT) %R% capture(one_or_more(DGT)) %R% END
evaluate_expression = function(n1, op, n2) {
n1 = as.numeric(n1)
n2 = as.numeric(n2)
switch(op,
"+" = n1 + n2,
"-" = n1 - n2,
"*" = n1 * n2,
"/" = n1 / n2)
}
result = input %>%
unite("result", 1:7, sep = "") %>%
extract(col = "result", into = c("n1", "op", "n2"), pattern) %>%
mutate(`Answer Expected` = pmap_dbl(list(n1, op, n2), evaluate_expression))
identical(result$`Answer Expected`, test$`Answer Expected`)
#> [1] TRUE
R solution 3 for Evaluate Concatenated Math Rows, proposed by Anil Kumar Goyal:
df <- read_excel("Excel/Excel_Challenge_472 - Operator in a grid.xlsx", range = cell_cols("A:G"))
df %>%
unite("answer", everything(), sep = "") %>%
mutate(answer = map_dbl(answer, ~eval(expr = parse(text = .))),
answer = sprintf(answer, fmt = "%.2f"))
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