3 rd grade math skills & strategies. problem of the day strategies 1.find (identify the...
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3rd GradeMath Skills &
Strategies
Problem of the Day Strategies1.Find (Identify the question)2.Know (Gather Information)3.Strategies:
Draw a pictureMake an organized listMake a tableMake a graphAct it outLook for a patternTry, check, reviseWrite an equationUse reasoning ALWAYS!! Work backwardsSolve a simpler problem
4. Show the problem (work it out)5. Solution (the answer to the problem)6. Answer (in a complete sentence)7. Check for reasonableness, evaluate (do the opposite: add/subtract, multiply/divide, etc.)
Word Problem Strategies1.Read the word
problem.2. Find and underline the question. 3. Box out key words & vocabulary words.4.Circle numbers you need, underline labels, mark out any distractors.5.Choose your strategy.6.Solve the problem (show your work!)7.Prove your answer.
•Watch for 2-step problems!•Watch for EXTRA or MISSING information!•Check answer for reasonableness!
•If labels are the same =
ADD or SUBTRACT!•If labels are different =
MULTIPLY or DIVIDE!
Place ValueStandard Number Form: 43,621
Word Form: Forty-three thousand, six hundred twenty-one
Expanded Notation: 40,000 + 3,000 + 600 + 20 + 1
Pizza Place Value: 43,621 (line the numbers up correctly and it will
40,000 look like a slice of pizza!) 3,000 600 20 1
HTO Chart: 100TH 10TH TH H T O 4 3 6 2 1
Digit: NumberValue: The worth of something.
PatternsRepeating Pattern:
Growing Pattern:
T-Chart: ---------------------------------- # of months
Number Pattern: 2, 4, 6, 8, __, 12, 14….
Teepee: ^ Rule: example=(+2)
A B C A
____Stem
____
^+2
1 Month
2 Months
3 Months
4 Months
5 Months?
# of leaves12345
1234?
Money“Hairy Money”
.
1 cent 5 cents 10 cents 25 cents 50 cents
Currency: the money that is used in a country.
1. Look at the hour hand (shortest) and say the number. If it is between the numbers you say the lowest number or the number before.
2. Look at the minute hand (longest), count by 5’s and say the number. If it is on 60, say “o’clock”.
Telling TimeAnalog: physical
measurementDigital: electronic signalQuarter Before: 15 minutes before the hourQuarter After: 15 minutes after the hour
Addition with Regrouping
1. Put big number on top to help remember for subtraction.
2. Make sure the numbers are lined up (ones with ones, tens with tens…)
3. Look at the ones place; if the two numbers equal ten or more you will regroup.
4. Bring the ones place down to the ones place and carry the ten to the tens place.
5. Look at the tens place and add the regrouped number.
6. Add all the numbers in the tens place. If the numbers equal ten or more you will regroup.
7. Repeat steps 3 and 5.
475+ 136_____ 611
The answer to an addition problem is called the SUM.
Sum, How many are there, Added/Plus, Total, In all, Altogether, And…
Subtraction with Regrouping“More on top, don’t stop!More on the floor, go next door!”
“Numbers the same, zeros the game!”
1. Place the bigger number on top.2. Make sure numbers are lined up (ones with
ones, tens with tens, etc.)3. Start at the ones place and look at the
numbers to see if you can subtract without regrouping.
4. If the top number is bigger, you can just subtract.
5. If the top number is smaller (less than) the bottom number, you have to regroup.
6. Take one ten from the tens place and cross it out (it becomes one less) (example: 3 turns into 2).
7. Add the ten to the ones place.8. Subtract the ones.9. Look at the tens & repeat steps 3-8.
The answer to a subtraction problem is called the DIFFERENCE.
How many more/less, How many are left, Spent, Difference…
Number LinesLook for the RULE!•Try numbers until you find the rule.
31, 37, ___, 49(Rule +6)
(Rule -5) 25 ___ 15 10
Don’t forget your teepees! (^)
2D & 3D Shapes
Rectangular
Prism
The corners are called VERTICES.
FaceEdgeSides
Vertices
Perimeter
Outside – Add ALL of the sides!
90 90 90+ 90-------
Perimeter: the length of the border.
Area
Inside – Count what you are looking for.
* Watch for shaded or NOT shaded!
Area: the amount of surface within a certain space.
MultiplicationWays to solve:
1.Loops & Groups
2. Array
3. Repeated addition
4. T-Chart
5. Algorithm (aka “up & over”)(you have to have your factsmemorized to use this method!)
3 X 4 3 44 X 3 X 4 X 3
----- -----
4 + 4 + 4 = 12
= 12
I I I I I I I I I I I I 4 . . . .3 . . . . . . . .
Gets bigger!
The answer to a multiplication problem is called a PRODUCT.
Product, Times, Twice,…
Greater & Less Than
Greater Than36 > 29
Less Than15 < 57
FractionsFraction-an equal part of a whole number.Numerator-tells us how many parts; “UP!”Denominator-tells us all the equal parts; “DOWN!”Equivalent-the same of equal.
3 1--- are shaded --- is not shaded4 4
Rounding – Part 1
•Estimate when you don’t need an exact answer.•Estimate to check your work.
“Round to the nearest…”“About how many,,,”“About”
When you see ESTIMATE or ABOUT,“round FIRST, then
solve”!
Rounding – Part 2
93-38
------
Rounds to
Rounds to 90-40
------ 50
Find the digit,
Look next door.
Five or higher,
Add one more!
Four or less,
Let it rest!
Find the digit,
Look next door.
Five or higher,
Add one more!
Four or less,
Let it rest!
Remember: When it’s in the middle (5), you round up! 25=30
0,1,2,3,4 = go to lowest 10
5,6,7,8,9 = go up to highest 10
Temperature F C
Boiling 212 100Freezing 32 0
Fact FamiliesAddition/Subtraction fact families are found
by:Starting with a simple fact. ( 2 + 5 = 7)Changing the numbers around. (5 + 2 = 7)Writing the Inverse operations for both. (7 - 2 = 5 & 7 - 5 = 2)
Multiplication/Division fact families are found by:Starting with a simple multiplication fact. ( 3 x 9 = 27)Changing the multiplicands around. (9 x 3 = 27)Writing the Inverse operations for both. (27 / 3 = 9 & 27 / 9 = 3)
Division Gets smaller!
Look for these words to divide: Separate, give, each, equal…
12 / 4 = 3
I I I I I I I I I I I I I I I I
Division Monster 12
The answer to a division problem is called a QUOTIENT.
Loops & Groups
Array I I I I I I I I I I I I
Separate, Equal, Half, Each (in the question)…
Measurement
12 inches = 1 foot = “your ruler” or “piece of paper”
3 feet = 36 inches = 1 yard = “yard stick”1 meter = “light on ceiling”1 mile = 5,280 feet = “school to Wal-Mart”1 inch = “end of finger”1 cm = 0.01 meter = “width of pinky”
CongruenceCongruent-same
size AND shape.
SymmetrySymmetry-one object that when an imaginary line is drawn through is the same at both ends.
Line of Symmetry-a line that divides a figure/shape into two mirror images.
Line of Symmetry
Graphs
Paired Numbers
•To make two batches of cookies how many eggs do you need? For three batches? For four batches? •How did you find the number of eggs needed to make four batches of cookies?
Probability
“More likely than”, “Less likely than”, “Equally likely as”…
Range
3 6
12-24
4X X
Lowest number Highest number
The number that only has 1 label.
The range (answer)
*With range, you will either multiply or divide.