Third Grade Mathematics

First Nine Weeks

 

Dear Parents:

These objectives listed below will be covered in the 1st Nine Weeks Unit of study.

Addition and Subtraction



 

Add and subtract within 1000 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.

 Use place value understanding to round whole numbers to the nearest 10 or 100.

 

 

Multiply and divide to solve problems



 

Multiply and divide within 100, using strategies such as the relationship between multiplication and division (e.g., knowing that 8 × 5 = 40, one knows 40 ÷ 5 = 8) or properties of operations.

(This will continue all school year)

 

 Understand division as an unknown-factor problem.

 

 

 

For example, find 32 ÷ 8 by finding the number that makes 32 when multiplied by 8.

 

Concepts of area



 

Relate area to the operations of multiplication and addition, show that the area is the same as would be found by multiplying the side lengths.

 

Geometry



 

Reason with shapes and understand their attributes.

 

Here are some suggestions as to what you can do at home to help your child

 

:

Many of the techniques for addition and subtraction are easily done mentally without recording. It is not at all unreasonable for students to be able to add and subtract two-digit numbers mentally by third grade. Recording of strategies helps communicate ideas and helps assist short term memory of the steps.

 Your child is learning to add and subtract numbers mentally. Your child can do mental math to find sums such as 200+400=600 or to estimate sums and differences. For example, 32+69=? As 30+70=100 so 32+69 is about 100.

 As you go through your daily activities encourage your child to add and subtract mentally. (Suggestion: when on a trip estimate how far a round trip would be if one way is 48 miles).



Number Challenge

Step 1

 

 

Make a set of digit cards by writing one digit on each card. Make a card for

each digit 0 – 9. Place the cards face down on the table. Player 1 turns over three

 

cards.

 

 

Step 2

Player 1 arranges the 3 digits to make the least possible 3-digit number and

records the number

Step 3

Player 2 then rearranges the cards to make the greatest possible number and

records it.

Step 4

Repeat the game several times using 3 digit numbers. Then play using 4 cards, 5

cards, or 6 cards to make larger numbers.

 Add Them Fast

Make number cards: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000

Step 1

Mix the number cards and place them face down on a table

Step 2

Each player turns over 2 cards and uses mental math to find the sum of the two

numbers shown. The player with the greater number keeps all 4 turned cards.

 Help your child "see" multiplication and division by using real items like raisins, coins, or paper squares, or by letting him draw items to represent the equations.

 Help your child understand shapes in different categories. For example, these shapes are examples of quadrilaterals, which are flat shapes with four straight sides.

*Rhombus - four-sided shape where all sides have equal length. Also, opposite sides are parallel and opposite angles are equal. A square would be a rhombus but a rectangle with unequal sides would not.

*Rectangle - rectangle is a four-sided polygon (a flat shape with straight sides) where every angle is a right angle (90°). A rectangle might be a square, but often is not a square.

*Square - A 4-sided polygon (a flat shape with straight sides) where all sides have equal length and every angle is a right angle (90°). A square is always a rectangle.

*Parallelogram - Opposite sides are parallel and equal in length, and opposite angles are equal (angles "a" are the same, and angles "b" are the same)

*Trapezoid - trapezoid is a quadrilateral with one pair of opposite sides parallel