Transcript Number Talks

MATH CURRICULUM
How do addition and
subtraction skills
th
develop from K-5
grade?
Kindergarten
Understand addition as putting together and adding to, and understand
subtraction as taking apart and taking from
K.OA1 Represent addition and subtraction with objects, fingers, mental images, drawings,
sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
K.OA2 Solve addition and subtraction word problems, and add and subtract within 10, e.g. by
using objects or drawings to represent the problem.
K.OA3 Decompose numbers less than or equal to 10 into pairs in more than one way, e.g. by
using objects or drawings, and record each decomposition by a drawing or equation (e.g. 5=
2 + 3 and 5 = 4+1)
K.OA4 For any number from 1 to 9, find the number that makes 10 when added to the given
number, e.g., by using objects or drawings, and record the answer with a drawing or
equation.
K.OA5 Fluently add and subtract within five
Work with numbers 11-19 to gain foundations for place value
K.NBT1 Compose and decompose numbers from 11 to 19 into ten ones and some
further ones, e.g., by using objects or drawings, and record each composition or
decomposition by a drawing or equation (e.g. 18 = 10 + 8); understand that these numbers
are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.
What does this look like in Kindergarten?
Equations with the = symbol in
different positions
Using drawings to solve problems
Number Bonds
Mental Strategies:
1st Grade
1.OA1 Use addition and subtraction within 20 to solve one and two step word
problems involving situations of adding to, taking from, putting together, taking
apart, and comparing, with unknowns in all positions, e.g. by using drawings and
equations with a symbol for the unknown number to represent the problem.
1.OA2 Solve word problems that call for addition of three whole numbers whose
sum is less than or equal to 20
1.OA6 Add and subtract within 20, demonstrating fluency for addition and
subtraction within 10.
1.OA7 Understand the meaning of the equal sign, and determine if equations
involving addition and subtraction are true or false. For example, which of the
following equations are true and which are false? 6=6, 7=8-1, 5+2=2+5 , 4+1=5+2
1.OA8 Determine the unknown whole number in an addition or subtraction
equation relating to three whole numbers. For example, determine the unknown
number that makes the equation true in each of the equations 8+ ? =11, 5 = □ – 3,
6+6 = □
1st Grade continued
Use place value understanding and properties of operations to add and
subtract
1.NBT4 Add within 100, including adding a two-digit number and a one-digit
number, and adding a two-digit number and a multiple of 10, using concrete
models or drawings and strategies based on place value, properties of operations,
and/or the relationship between addition and subtraction; relate the strategy to a
written method and explain the reasoning used. Understand that in adding twodigit numbers, one adds tens and tens, ones and ones, and sometimes it is
necessary to compose a ten.
What does this look like in 1st grade?
Adding a 2 digit number and a multiple
of 10 by
a) drawing Base10 blocks
b) making jumps of 10 on an empty
number line
45 + 30 = 75
2nd Grade
Represent and solve problems involving addition and subtraction
2.OA1 Use addition and subtraction within 100 to solve one and two step word
problems involving situations of adding to, taking from, putting together, taking
apart, and comparing, with unknowns in all positions, e.g. by using drawings and
equations with a symbol for the unknown number to represent the problem.
Add and subtract within 20
2.OA2 Fluently add and subtract within 20 using mental strategies. By end of
Grade 2, know from memory all sums of two one-digit numbers.
Use place value understanding and properties of operations to add and
subtract
2.NBT5 Fluently add and subtract within 100 using strategies based on place
value, properties of operations, and/or the relationship between addition and
subtraction.
2.NBT6 Add up to four two-digit numbers using strategies based on place value and
properties of operations.
2nd Grade continued
2.NBT7 Add and subtract within 1000, using concrete models or drawings and
strategies based on place value, properties of operations, and/or the relationship
between addition and subtraction; relate the strategy to a written method.
Understand that in adding or subtracting three-digit numbers, one adds or
subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it
is necessary to compose or decompose tens or hundreds.
2.NBT8 Mentally add 10 or 100 to a given number 100-900 and mentally subtract
10 or 100 from a given number 100-900.
2.NBT9 Explain why addition and subtraction strategies work, using place value and
the properties of operations.
What does this look like in 2nd grade?
3rd Grade
3.NBT2 Fluently add and subtract within 1000 using strategies
and algorithms based on place value, properties of
operations, and/or the relationship between addition and
subtraction.
What does this look like in 3rd grade?
Decompose into hundreds, tens and ones and recombine (or
subtract) with and without regrouping
4th Grade
4.OA3 Solve multistep word problems posed with whole numbers and
having whole-number answers using the four operations, including
problems in which remainders must be interpreted. Represent these
problems using equations with a letter standing for the unknown quantity.
Assess the reasonableness of answers using mental computation and
estimation strategies including rounding.
4.NBT4 Fluently add and subtract multi-digit whole numbers using the
standard algorithm.
What does this look like in 4th grade?
5th Grade
5.NBT7 Add, subtract, multiply, and divide decimals to hundredths, using
concrete models or drawings and strategies based on place value,
properties of operations, and/or the relationship between addition and
subtraction, relate the strategy to a written method and explain the
reasoning used.
What does this look like in 5th grade?
Assessments
Common Core Resources for Parents
Questions?