Skills available for Colorado second-grade math standards
Standards are in bold, followed by a list of the IXL math skills that are aligned to that standards. Students can practice these skills online at www.ixl.com.
2.1.1 The whole number system describes place value relationships through 1,000 and forms the foundation for efficient algorithms
2.1.1.a Use place value to read, write, count, compare, and represent numbers.
2.1.1.a.i Represent the digits of a three-digit number as hundreds, tens, and ones.
Place value models - tens and ones (2-M.1)
Place value models - up to hundreds (2-M.2)
Place value - tens and ones (2-M.5)
Place value - up to hundreds (2-M.6)
Convert to/from a number - tens and ones (2-M.8)
2.1.1.a.ii Count within 1000.
Counting patterns - up to 100 (2-A.4)
Counting patterns - up to 1,000 (2-A.14)
2.1.1.a.iii Skip-count by 5s, 10s, and 100s.
Skip-counting (2-A.1)
Skip-counting sequences (2-A.3)
2.1.1.a.iv Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.
Writing numbers up to 100 in words - convert words to digits (2-C.2)
Writing numbers up to 1,000 in words - convert words to digits (2-C.4)
Convert from expanded form - up to hundreds (2-M.14)
2.1.1.a.v Compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using >, =, and < symbols to record the results of comparisons.
Comparing numbers up to 1,000 (2-B.2)
Put numbers up to 100 in order (2-B.3)
Put numbers up to 1,000 in order (2-B.4)
Greatest and least - word problems - up to 100 (2-B.5)
Greatest and least - word problems - up to 1,000 (2-B.6)
2.1.1.b Use place value understanding and properties of operations to add and subtract.
2.1.1.b.i Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
Add a two-digit and a one-digit number - without regrouping (2-G.3)
Add a two-digit and a one-digit number - with regrouping (2-G.4)
Add two two-digit numbers - without regrouping (2-G.5)
Add two two-digit numbers - with regrouping (2-G.6)
Addition input/output tables - up to two digits (2-G.7)
Ways to make a number using addition (2-G.8)
Balance addition equations - up to two digits (2-G.12)
Subtract a one-digit number from a two-digit number - without regrouping (2-H.3)
Subtract a one-digit number from a two-digit number - with regrouping (2-H.4)
Subtract two two-digit numbers - without regrouping (2-H.5)
Subtract two two-digit numbers - with regrouping (2-H.6)
Subtraction input/output tables - up to two digits (2-H.7)
Ways to make a number using subtraction (2-H.8)
Balance subtraction equations - up to two digits (2-H.12)
Add and subtract numbers up to 100 (2-L.8)
Addition and subtraction - ways to make a number - up to 100 (2-L.9)
Addition and subtraction - balance equations - up to 100 (2-L.11)
Which sign (+ or -) makes the number sentence true? (2-L.15)
2.1.1.b.ii Add up to four two-digit numbers using strategies based on place value and properties of operations.
Add three numbers up to two digits each (2-G.13)
2.1.1.b.iii 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.
Add doubles using models (2-E.9)
Addition with three-digit numbers (2-I.3)
Addition input/output tables - up to three digits (2-I.4)
Addition word problems - up to three digits (2-I.5)
Complete the addition sentence - up to three digits (2-I.6)
Write the addition sentence - up to three digits (2-I.7)
Balance addition equations - up to three digits (2-I.8)
Subtract three-digit numbers (2-J.3)
Subtraction input/output tables - up to three digits (2-J.4)
Subtraction word problems - up to three digits (2-J.5)
Complete the subtraction sentence - up to three digits (2-J.6)
Write the subtraction sentence - up to three digits (2-J.7)
Balance subtraction equations - up to three digits (2-J.8)
Regroup tens and ones - ways to make a number (2-M.9)
Regroup tens and ones (2-M.10)
2.1.1.b.iv Mentally add 10 or 100 to a given number 100-900, and mentally subtract 10 or 100 from a given number 100-900.
Add multiples of 10 (2-G.1)
Subtract multiples of 10 (2-H.1)
Add multiples of 100 (2-I.1)
Subtract multiples of 100 (2-J.1)
2.1.1.b.v Explain why addition and subtraction strategies work, using place value and the properties of operations.
Related addition facts (2-K.1)
Related subtraction facts (2-K.2)
Fact families (2-K.3)
Solve inequalities using addition and subtraction shortcuts (2-K.5)
2.1.2 Formulate, represent, and use strategies to add and subtract within 100 with flexibility, accuracy, and efficiency
2.1.2.a Represent and solve problems involving addition and subtraction.
2.1.2.a.i 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.
Comparing numbers up to 100 (2-B.1)
Review - writing addition sentences - sums to 10 (2-E.3)
Addition with pictures - sums to 20 (2-E.4)
Write addition sentences to describe pictures - sums to 20 (2-E.5)
Addition word problems - one digit (2-E.12)
Complete the addition sentence - one digit (2-E.13)
Write the addition sentence - one digit (2-E.14)
Balance addition equations - one digit (2-E.15)
Add three one-digit numbers (2-E.17)
Add three one-digit numbers: word problems (2-E.18)
Add four or more one-digit numbers: word problems (2-E.20)
Review - writing subtraction sentences - up to 10 (2-F.3)
Subtraction with pictures (2-F.5)
Write subtraction sentences to describe pictures - up to 18 (2-F.6)
Subtraction word problems - up to 18 (2-F.10)
Complete the subtraction sentence - up to 18 (2-F.11)
Write the subtraction sentence - up to 18 (2-F.12)
Balance subtraction equations - up to 18 (2-F.13)
Write addition sentences to describe pictures (2-G.2)
Addition word problems - up to two digits (2-G.9)
Complete the addition sentence - up to two digits (2-G.10)
Write the addition sentence - up to two digits (2-G.11)
Balance addition equations - up to two digits (2-G.12)
Add three numbers up to two digits each: word problems (2-G.14)
Add four or more numbers up to two digits each: word problems (2-G.16)
Write subtraction sentences to describe pictures - up to two digits (2-H.2)
Subtraction word problems - up to two digits (2-H.9)
Complete the subtraction sentence - up to two digits (2-H.10)
Write the subtraction sentence - up to two digits (2-H.11)
Balance subtraction equations - up to two digits (2-H.12)
Addition and subtraction word problems - up to 20 (2-L.3)
Addition and subtraction - balance equations - up to 20 (2-L.4)
Input/output tables - write the rule - up to 20 (2-L.6)
Addition and subtraction word problems - up to 100 (2-L.10)
Input/output tables - write the rule - up to 100 (2-L.12)
Write addition and subtraction sentences (2-L.16)
Customary units of length: word problems (2-S.4)
Metric units of length: word problems (2-S.10)
2.1.2.a.ii Apply addition and subtraction concepts to financial decision-making.
Add money - up to $1 (2-P.9)
Add money - up to $1: word problems (2-P.10)
Subtract money - up to $1 (2-P.11)
Subtract money - up to $1: word problems (2-P.12)
Add and subtract money - up to $1 (2-P.13)
Add and subtract money - up to $1: word problems (2-P.14)
How much more to make a dollar? (2-P.19)
Making change (2-P.20)
2.1.2.b Fluently add and subtract within 20 using mental strategies.
Review - add one-digit numbers - sums to 10 (2-E.1)
Review - ways to make a number - sums to 10 (2-E.2)
Add one-digit numbers (2-E.6)
Addition input/output tables - sums to 20 (2-E.7)
Add zero (2-E.8)
Add doubles (2-E.10)
Balance addition equations - one digit (2-E.15)
Review - subtract one-digit numbers - up to 10 (2-F.1)
Review - ways to subtract - up to 10 (2-F.2)
Subtract a one-digit number from a two-digit number up to 18 (2-F.7)
Subtraction input/output tables - up to 18 (2-F.8)
Subtract zero/all (2-F.9)
Balance subtraction equations - up to 18 (2-F.13)
Add and subtract numbers up to 20 (2-L.1)
Addition and subtraction - ways to make a number - up to 20 (2-L.2)
Addition and subtraction - balance equations - up to 20 (2-L.4)
2.1.2.c Know from memory all sums of two one-digit numbers.
Review - add one-digit numbers - sums to 10 (2-E.1)
Review - ways to make a number - sums to 10 (2-E.2)
Addition with pictures - sums to 20 (2-E.4)
Add one-digit numbers (2-E.6)
Add zero (2-E.8)
Add doubles - complete the sentence (2-E.11)
Addition word problems - one digit (2-E.12)
Complete the addition sentence - one digit (2-E.13)
Balance addition equations - one digit (2-E.15)
Addition equations: true or false? (2-E.16)
2.1.2.d Use equal groups of objects to gain foundations for multiplication.
2.1.2.d.i Determine whether a group of objects (up to 20) has an odd or even number of members.
Even or odd (2-A.9)
Identify numbers as even or odd (2-A.11)
Select even or odd numbers (2-A.12)
2.1.2.d.ii Write an equation to express an even number as a sum of two equal addends.
2.1.2.d.iii Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.
Identify repeated addition in arrays: sums to 10 (2-E.21)
Write addition sentences for arrays: sums to 10 (2-E.22)
Identify repeated addition in arrays: sums to 25 (2-E.23)
Write addition sentences for arrays: sums to 25 (2-E.24)
Count equal groups (2-Y.1)
Write multiplication sentences for equal groups (2-Y.3)
2.3 Data Analysis, Statistics, and Probability
2.3.1 Visual displays of data can be constructed in a variety of formats to solve problems
2.3.1.a Represent and interpret data.
2.3.1.a.i Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.
Interpret line plots (2-R.5)
Create line plots (2-R.6)
2.3.1.a.ii Draw a picture graph and a bar graph (with single-unit scale) to represent a data set with up to four categories.
Interpret bar graphs (2-R.2)
Which bar graph is correct? (2-R.3)
Create bar graphs (2-R.4)
Interpret pictographs (2-R.7)
Create pictographs (2-R.8)
Create bar graphs (3-U.7)
2.3.1.a.iii Solve simple put together, take-apart, and compare problems using information presented in picture and bar graphs.
Interpret tally charts and tables (2-R.1)
Interpret bar graphs (2-R.2)
Interpret pictographs (2-R.7)
2.4 Shape, Dimension, and Geometric Relationships
2.4.1 Shapes can be described by their attributes and used to represent part/whole relationships
2.4.1.a Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces.
Count sides and vertices (2-T.3)
Compare sides and vertices (2-T.4)
Select three-dimensional shapes (2-U.2)
Count vertices, edges, and faces (2-U.3)
2.4.1.b Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.
Count shapes in a Venn diagram (2-R.11)
Sort shapes into a Venn diagram (2-R.12)
Name the two-dimensional shape (2-T.1)
Select three-dimensional shapes (2-U.2)
2.4.1.c Partition a rectangle into rows and columns of same-size squares and count to find the total number of them.
Area (2-V.3)
2.4.1.d Partition circles and rectangles into two, three, or four equal shares, describe the shares using the words halves, thirds, half of, a third of, etc., and describe the whole as two halves, three thirds, four fourths.
Halves, thirds, and fourths (2-W.2)
Identify the fraction (2-W.3)
Fraction models equivalent to whole numbers (2-W.10)
2.4.1.e Recognize that equal shares of identical wholes need not have the same shape.
Halves, thirds, and fourths (2-W.2)
Identify the fraction (2-W.3)
2.4.2 Some attributes of objects are measurable and can be quantified using different tools
2.4.2.a Measure and estimate lengths in standard units.
2.4.2.a.i Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
Choose the appropriate measuring tool (2-S.15)
2.4.2.a.ii Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
Which customary unit of length is appropriate? (2-S.3)
Which metric unit of length is appropriate? (2-S.9)
2.4.2.a.iii Estimate lengths using units of inches, feet, centimeters, and meters.
Measure using an inch ruler (2-S.2)
Which customary unit of length is appropriate? (2-S.3)
Measure using a centimeter ruler (2-S.8)
Which metric unit of length is appropriate? (2-S.9)
2.4.2.a.iv Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit.
2.4.2.b Relate addition and subtraction to length.
2.4.2.b.i Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units and equations with a symbol for the unknown number to represent the problem.
Customary units of length: word problems (2-S.4)
Metric units of length: word problems (2-S.10)
2.4.2.b.ii Represent whole numbers as lengths from 0 on a number line diagram and represent whole-number sums and differences within 100 on a number line diagram.
Number lines - up to 100 (2-A.6)
2.4.2.c Solve problems time and money.
2.4.2.c.i Tell and write time from analog and digital clocks to the nearest five minutes, using a.m. and p.m.
Match digital clocks and times (2-Q.1)
Match analog clocks and times (2-Q.2)
Match analog and digital clocks (2-Q.3)
Read clocks and write times (2-Q.5)
A.M. or P.M. (2-Q.7)
Compare clocks (2-Q.8)
Time patterns (2-Q.11)
2.4.2.c.ii Solve word problems involving dollar bills, quarters, dimes, nickels, and pennies, using $ and ¢ symbols appropriately.
Names and values of common coins (2-P.1)
Names and values of all coins (2-P.2)
Count money - up to $1 (2-P.4)
Count money - up to $5 (2-P.5)
Equivalent amounts of money - up to $1 (2-P.6)
Exchanging coins (2-P.7)
Comparing groups of coins (2-P.8)
Add and subtract money - up to $1 (2-P.13)
Add and subtract money - up to $1: word problems (2-P.14)
Purchases - do you have enough money - up to $1 (2-P.15)
Purchases - do you have enough money - up to $5 (2-P.16)