One |
- Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones 2.NBT.1,3
- Compare three-digit numbers based on hundreds, tens, and ones , using >, =, and < symbols. 2.NBT.4
- Mentally add 10 or 100 2.NBT.8
- Use addition and subtraction within 100 to solve one-step word problems. 2.OA.1
- Use place value strategies (decomposition, partial sums or renaming to add and subtract within 100). 2.NBT.5
|
number of tens | Given the number 286, students know that there are 8 tens in that number. | value of tens | Given the number 286, students recognize that the value of those 8 tens is 80. | number of hundreds | Given the number 286, students know that there are 2 hundreds in that number. | value of hundreds | Given the number 286, students recognize that the value of those 2 hundreds is 200. | greater than 
| Identifying a number that is more, when it is given first . Ex. 56 is greater than 53. 56 > 53 | less than 
| Identifying a lesser number when it is given first. Ex. 53 is less than 56. 53 < 56 |
addition strategy: decomposition | Students first decompose the numbers into tens and ones. 56 + 88 = ____
56 = 50 + 6 88 = 80 + 8
Students then add the tens to get part of the sum, and add the ones to get the other part of the sum.
56 = 50 + 6 +88 = 80 + 8 130 +14
Finally, they put those partial sums together (130 + 14) to find the sum, which in this problem is 144.
*This strategy is powerful because it promotes mental math - the ultimate efficient strategy.* | addition strategy: partial sums | This is a more efficient way to record the decomposition strategy. Students find the partial sums using place value understandings.
56 + 88 130 (Think 50 + 80 = 130) 14 (Think 6 + 8 = 14) 144 |
|
Base Ten Fun allows students to practice building numbers with virtual base ten blocks. There are “read and make”, “listen and make” and “count and write” options. It can be adjusted to include hundreds. (http://www.abcya.com/base_ten_fun.htm)
Base Ten Bingo also allows for practice with base ten blocks in a virtual space. It can be adjusted to include hundreds. (http://www.abcya.com/base_ten_bingo.htm)
Compare Numbers This game can be set to compare numbers to 100, which is a perfect match for the grade one standards. (http://www.crickweb.co.uk/ks2numeracy-calculation.html#ncmenu)
Fruit Splat Addition This game has options which include 1 and 2 digit numbers with regrouping. (http://www.sheppardsoftware.com/mathgames/fruitshoot/fruitshoot_addition.htm)
Building Expressions A fun game that helps students practice addition and subtraction within 20. (http://v7.k12.com/sample_lessons/activities/images/swfs/building_expressions_final.swf) |
Two
|
- Estimate and measure the length of an object by selecting and using tools such as rulers, yardsticks, meter sticks, and measuring tapes.
- 2.MD.1; 2.MD.3
- Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit. - 2.MD.4
- Tell and write time from analog and digital clocks to the nearest five minutes, using a.m. and p.m. - 2.MD.7
- Recognize and draw 2d and 3d shapes given the number of angles or a given the number of equal faces. (Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.) - 2.G.1
- Use addition and subtraction within 100 to solve two-step word problems. 2.OA.1
|
length units | Students in grade two measure in these length units: centimeters, inches, yards and meters. | analog and digital clocks | 
| quadrilateral | A 2d shape with 4 straight sides. 
| pentagon | A 2d shape with 5 straight sides. 
| hexagon | A 2d shape with 6 straight sides. 
|
equation | A statement that two math values are equal. Ex. 3 + 3 = 6 or 6 = 3 + 3 (We purposely vary the side that includes the sum and the side that includes the expression to emphasize the equality.) |
expression | Numbers and operators grouped together to show a value. (They do not include an equal sign.) Ex. 3 + 3 or 5 + 1 |
sum | The answer to an addition problem. Ex. 4 + 5 = 9; 9 is the sum |
difference | The answer to a subtraction problem. Ex. 7-2 = 5; 5 is the difference |
givens | The important information in a story problem that we can use to solve it. Ex. (The givens are in bold in the story problem below.)
Tom saw 3 birds on a tree and 2 birds on a fence. How many birds did Tom see in all? |
goal | The question or “ask” in a story problem. Ex. (The goal is in bold in the story problem below.)
Tom saw 3 birds on a tree and 2 birds on a fence. How many birds did Tom see in all? |
|
Harcourt Ruler Dragger Centimeters This activity allows students to move a virtual ruler to measure objects in centimeters. (http://www.harcourtschool.com/activity/length_strength1_centi/)
Harcourt Ruler Dragger Inches This activity allows students to move a virtual ruler to measure objects in centimeters. (http://www.harcourtschool.com/activity/length_strength1_inches/)
Stop the Clock Fun game to practice telling time to 5 minutes with analog and digital clocks. (http://www.teachingtime.co.uk/draggames/sthec3.html)
Word Problems with Katie Practice with one-step addition and subtraction word problems. (http://www.mathplayground.com/WordProblemsWithKatie1.html)
Thinking Blocks Practice with two-step adding and subtracting word problems. A visual model can be manipulated by students to support understanding. (http://www.mathplayground.com/tb_addition/thinking_blocks_addition_subtraction.html) |
Three |
- Add up to four two-digit addends using strategies based on place value (partial sums and decomposition) and properties of operations (commutative and associative). 2.NBT.6
- Solve word problems involving dollar bills, quarters, dimes, nickels, and pennies, using $ and ¢ symbols appropriately 2.MD.8
- Add and subtract within 1000, using base ten bocks and drawings and strategies based on place value (partial sums, renaming and decomposition) and properties of operations (commutative and associative). Compose or decompose tens or hundreds when necessary. 2.NBT.7
- Fluently add and subtract within 20 using mental strategies. Know from memory all sums of two one-digit numbers.
2.OA.2
|
addends | Numbers that are being added together in an equation. Ex. 33 + 44 + 18 = 95; the 33, 44 and 18 are addends. |
commutative | The math property that allows you to swap numbers around when adding, because you still get the same sum. Ex. 51+67=118 and 67+51=118. You can switch the order of the 67 and 51 because of this property. |
associative | The math property that allows you to group numbers in different ways when you add, because you still get the same sum. Ex. (6+1) + 2 = 9 because 7 + 2 = 9 and 6 + (1+2) = 9. because 6 + 3 = 9. We can add these numbers in any order because of this property. |
regrouping in addition | Students will need to regroup ones into a new ten. Ex. 37 + 48 = 85 Students recognize that 7 + 8 = 15. This is a ten and five ones. They add that ten to the thirty and forty to get 80, which added to the 5 equals 85.
Students will need to regroup tens into a new hundred. Ex. 366 + 291 = 657 Students recognise that 60 + 90 = 150. They add that new hundred to the 300 and 200 to get 600. They then add the 50 and the 7 to that to get a sum of 657. |
fluency |
Fluency is knowing a math fact in 3-4 seconds.
|
subtraction strategy: renaming
| Students first decompose numbers into tens and ones. 62 - 37 = ___
62 = 60 + 2 - 37 = 30 + 7
They recognize that they need more ones in order to subtract, since 2 - 7 gives you a negative number.
Students rename 62 so that there are more ones. 62 = 50 + 12. They then subtract tens and ones to find the partial differences. 62 = 50 + 12 - 37 = 30 + 7 20 + 5
Students recompose (put back together) the two partial differences to find the difference of 25.
This strategy helps students move to the traditional subtraction algorithm in later grades with place value understanding. |
|
Virtual Base Ten Blocks Students can access virtual base ten blocks at this site. They can use them to solve addition and subtraction problems. (http://www.glencoe.com/sites/common_assets/mathematics/ebook_assets/vmf/VMF-Interface.html)
Counting Money This game supports students as they gain fluency with counting a variety of coins. (http://www.hbschool.com/activity/counting_money/)
Games and sites to promote fact fluency
Number Bonds to 20 (http://www.mathplayground.com/number_bonds_20.html)
Math Man Addition (http://www.mathplayground.com/mathman_addition.html) Minus Mission (http://www.mathplayground.com/ASB_MinusMission.html)
Penguin Game (http://www.sheppardsoftware.com/mathgames/popup/popup_addition.htm)
Math Magician (http://oswego.org/ocsd-web/games/mathmagician/cathymath.html)
XtraMath (https://xtramath.org)
|