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.