Grade 2 Grade 2

In
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the
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63
63
63–––37
37
37===26
26
26
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demonstrate
demonstrateboth
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and
and
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This
example
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the
subtraction.This
Thisexample
exampleshows
showsthe
the
problem
problem
problem82
82
82–––39.
39.
39.
Parent
Parent
Roadmap
Roadmap
Grade
Grade 22
Second
Second
Secondgraders
graders
gradersuse
use
usetheir
their
theirknowledge
knowledge
knowledgeof
ofof
addition
addition
additionand
and
andsubtraction
subtraction
subtractionto
totosolve
solve
solveoneoneone-and
and
and
two-step
word
problems.
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sample
two-step
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wordproblems.
problems.The
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sample
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farmer
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andsome
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45
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
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82
82
82–––39
39
39===43
43
43
In
InInthe
the
thesame
same
sameway,
way,
way,subtraction
subtraction
subtractioncan
can
canbe
be
beshown
shown
shown
on
on
onaaanumber
number
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line.
line.This
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student
studentstarted
started
startedat
atat37
37
37
and
and
counted
up
toto63
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find
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26.
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555 333
45
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45–––555===40
40
40
40
40–––333===37
37 There
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Adding
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and
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understoodby
by
by
using
using
usingexpanded
expanded
expandednotation.
notation.
notation.
63
63
63–––37
37
37===26
26
26
Students
Students
Studentsuse
use
useplace
place
placevalue
value
valueunderstanding
understanding
understandingto
toto
solve
solve
solvethese
these
theseproblems.
problems.
problems.
The
The
Thehundreds
hundreds
hundredschart
chart
chartcan
can
canbe
be
beused
used
usedfor
for
forstudents
students
students
to
totodemonstrate
demonstrate
demonstrateboth
both
bothaddition
addition
additionand
and
and
subtraction.
subtraction.
subtraction.This
This
Thisexample
example
exampleshows
shows
showsthe
the
the
problem
problem
problem82
82
82–––39.
39.
39.
Cobb
Cobb
CobbCounty
County
CountySchools
Schools
Schools
Strategies
Strategiesfor
for
foraddition
addition
additionand
and
and
Strategies
subtraction
subtraction
subtraction
2013-2014
2013-2014
2013-2014
Parent
Parent
Roadmap
Roadmap
Grade
Grade 22
Second
Second
Secondgraders
graders
gradersuse
use
usetheir
their
theirknowledge
knowledge
knowledgeof
ofof
addition
addition
additionand
and
andsubtraction
subtraction
subtractionto
totosolve
solve
solveoneoneone-and
and
and
two-step
two-stepword
wordproblems.
problems.The
Thesample
sample
two-step
word
problems.
The
sample
below
below
belowshows
shows
showsaaatwo-step
two-step
two-stepproblem.
problem.
problem.
AAAfarmer
farmer
farmerhad
had
had888cows
cows
cowsand
and
andsome
some
somehorses
horses
horsesinininaaa
field.
field.
field.There
There
Therewere
were
were45
45
45animals
animals
animalsinininthe
the
thefield.
field.
field.
Later,
Later,
Later,the
the
thefarmer
farmer
farmersent
sent
sent666more
more
morehorses
horses
horsesinto
into
into
the
thefield.
field.What
Whatisisisthe
thetotal
totalnumber
numberof
the
field.
What
the
total
number
ofof
horses
horsesinininthe
thefield?
field?
horses
the
field?
888+++
45
45

===45
The
The
Thestudent
student
studentwould
would
wouldstart
start
startby
by
bysubtracting
subtracting
subtracting888
(cows)
(cows)
(cows)from
from
fromthe
the
thetotal
total
total45
45
45(animals).
(animals).
(animals).
45
45
45–––888
This
This
Thisstudent
student
studentstarted
started
startedat
atat82
82
82and
and
andmoved
moved
movedback
back
back30
30
30
to
totoland
land
landon
on
on52.
52.
52.The
The
Thenext
next
nextstep
step
stepwas
was
wasto
totocount
count
count
back
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back999and
and
andland
land
landon
on
on43.
43.
43.
82
82
82–––39
39
39===43
43
43
555 333
45
45
45–––555===40
40
40
40
40–––333===37
37 There
40
37
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37
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IfIfIf666more
morehorses
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wereadded
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thefield
field
more
horses
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the
field
that
thatwould
wouldmean
meanthere
therewas
wasaaatotal
totalof
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that
would
mean
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total
ofof43
43
horses.
horses.
horses.
37
37
37+++666===43
43
43
Cobb
Cobb
CobbCounty
County
CountySchools
Schools
Schools
Strategies
Strategiesfor
for
foraddition
addition
additionand
and
and
Strategies
subtraction
subtraction
subtraction
2013-2014
2013-2014
2013-2014
Math
Math
Math
MathFact
FactStrategies
Strategies
Below
Belowisisa astrategy
strategythat
thatmight
mightbebeused
usedtoto
assist
assistsecond
secondgraders
gradersininthinking
thinkingabout
about
subtraction
subtractionwhen
whenworking
workingwith
withfacts.
facts.
24
24−−99==
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with
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22 44
10
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14
This
Thisexample
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ten
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Secondgraders
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alsoadd
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Thisexample
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whicha astudent
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44 55
24
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numbers
numbersrepresent
representamounts
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tens
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andones.
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base
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numbers.
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348
348ones
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348
300
300+ +4040+ +8 8
69
69 == 304
304
26
26++37
37==
26
26++37
37==
26
26++37
37
26
26++40
40==66
66
66
66––33==63
63
11hundred
hundred
++
AAgoal
goalininsecond
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forstudents
studentstotoadd
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mentally
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making
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66++88==
66++66++22==
66++22++88==
OR
66++66==12
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88++88==16
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12++22==14
14
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16−−22==14
14
Second
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26
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23
64
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Another
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students
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++19
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addition
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70
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83
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26
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37==63
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Math
Math
Math
MathFact
FactStrategies
Strategies
Below
Belowisisa astrategy
strategythat
thatmight
mightbebeused
usedtoto
assist
assistsecond
secondgraders
gradersininthinking
thinkingabout
about
subtraction
subtractionwhen
whenworking
workingwith
withfacts.
facts.
22 44
10
10++44==14
14
This
Thisexample
exampleshows
showshow
howmaking
makinga aten
ten
makes
makesititeasier
easiertotoquickly
quicklyadd.
add.
Second
Secondgraders
gradersalso
alsoadd
addusing
usingthe
thedoubles
doubles
strategy.
strategy.This
Thisexample
exampleshows
showstwo
twoways
waysinin
which
whicha astudent
studentcan
canadd
add6 6+ +8.8.
This
Thisstudent
studentadjusted
adjustedthese
thesefacts
factstotoquickly
quickly
add
addthem.
them.
Second
Secondgraders
gradersmove
moveinto
intoaddition
additionusing
using
base
basetens
tenstotorepresent
representthe
theproblem.
problem.They
They
then
thenmove
movetotousing
usingnumbers.
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++
44 55
24
24––44==20
20
20
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15
235
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Working
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withBase
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Place
Placevalue
valueisisa aprimary
primaryfocus
focusfor
forsecond
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graders.
graders.Students
Studentsneed
needtotounderstand
understandthat
that
numbers
numbersrepresent
representamounts
amountsofofhundreds,
hundreds,
tens
tensand
andones.
ones.This
Thisbegins
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workingwith
with
126
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numbers.
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69
69 == 304
304
26
26++37
37==
26
26++37
37==
26
26++37
37
26
26++40
40==66
66
66
66––33==63
63
11hundred
hundred
++
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66++88==
66++66++22==
66++22++88==
OR
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resume,
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pleasevisit
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24
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sums.
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26
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De la misma manera, la resta se puede
mostrar en una recta numérica. Este
estudiante comenzó a las 37 y contó hasta 63
para encontrar una diferencia de 26.
Sumando y restando se puede entender
mediante el uso de la notación expandida.
63 – 37 = 26
Los estudiantes usan el valor posicional
entendimiento para resolver estos
problemas.
El cartel de centenas se puede utilizar para
que los estudiantes demuestren tanto la
suma y la resta. Este ejemplo muestra el
problema 82-39.
Guía de ruta
para Padres
Grado 2
Alumnos de segundo grado usan su
conocimiento de la suma y la resta para
resolver problemas de palabras de una y
dos etapas. El siguiente ejemplo muestra un
problema de dos pasos.
Un granjero tenía 8 vacas y algunos
caballos en un campo. Había 45 animales
en el campo. Más tarde, el granjero envió 6
caballos más en el campo. ¿Cuál es el
número total de caballos en el campo?
8+
 = 45
El estudiante comenzará restando 8 (vacas)
del total de 45 (animales).
45 – 8
Este estudiante comenzó a los 82 y regresó
30 para llegar a 52. El siguiente paso fue
contar hacia atrás 9 y llegar a 43.
82 – 39 = 43
5 3
45 – 5 = 40
40 – 3 = 37
Escuelas del Condado
de Cobb
Hay 37 caballos.
Si se agregaron 6 caballos más en ese
campo significaría que había un total de 43
caballos.
37 + 6 = 43
Estrategias para la adición
y la resta
2013-2014
Matemáticas
Estrategias Informativas
Matemáticas
A continuación se muestra una estrategia
que podría utilizarse para ayudar a los
estudiantes de segundo grado en la reflexión
sobre la resta cuando se trabaja con hechos.
24 − 9 =
Los estudiantes de grado 2 continúan con
las estrategias aprendidas en el grado 1.
Este ejemplo muestra cómo hacer un diez
lo hace más fácil para agregar
rápidamente.
Valor Place es un foco principal de segundo
grado. Los estudiantes deben entender que
los números representan cantidades de
centenas, decenas y unidades. Esto comienza
126
por trabajar con decenas de bases
128 =
Alumnos de segundo grado también agregan
utilizando la estrategia de dobles. Este
ejemplo muestra dos formas en las que un
estudiante puede añadir 6 + 8.
6+6+2=
6 + 6 = 12
12 + 2 = 14
OR
235
Trabajar con decenas de Base
10 + 4 = 14
6+8=
+
4 5
24 – 4 = 20
20 – 5 = 15
8+6=
2 4
Alumnos de segundo grado siguen en
adición con decenas de base para
representar el problema. A continuación,
pasaran a la utilización de números.
6+2+8=
8 + 8 = 16
16 − 2 = 14
Este estudiante ajusta estos hechos para
agregar rápidamente.
2 decenas
3 ciens
4 decenas
8 unidades
8 unidades
34 decenas
8 unidades
348 unidades
= 304
26 + 37 =
26 + 37 =
+3
Los estudiantes necesitan entender el
significado de los números.
69
Un objetivo en el segundo grado es
que los estudiantes añaden mentalmente
utilizando estrategias. Una estrategia es
hacer una serie amistosa.
26 + 37
26 + 40 = 66
66 – 3 = 63
1 cien
+
OR
−3
+3
26 + 37
23 + 40 =63
64 + 19 = 83
Otra estrategia para ayudar a
estudiantes a entender
Además implica trabajar
con sumas parciales.
64
+ 19
13
70
83
348
300 + 40 + 8
Los estudiantes de segundo grado comienzan a
sumar y restar hasta 20. Ellos sabrán de
memoria sus operaciones de suma al final de
segundo grado.
Los estudiantes de segundo grado pueden
usar una línea numérica para mostrar
problemas de suma. 26 + 37 = 63
+ 10
37
+ 10 + 1 + 1 + 1 + 1 + 1 + 1
47
57 58 59 60 61 62 63