3rd Grade Teaching Strategies 1. Array/Area Model- a set of objects or numbers arranged in order, often in rows and columns. Arrays and area models ar...
3rd Grade Teaching Strategies 1. Array/Area Model- a set of objects or numbers arranged in order, often in rows and columns. Arrays and area models are different in that an area model is composed of squares that are connected. Multiplication- 3 rows, 5 objects per row
Division- 12 objects, 4 groups
3 x 5 = 15 objects
12 ÷ 4 = 3 objects per group
Array
Area Model
2. Bar Model- a visual representation of the information in word problems using bar units. Addition- Melissa has 50 blue beads and 20 red beads. How many beads does she have
altogether?
?
50 + 20 = 70
50
20
Subtraction- Ben and Andy have 90 toy cars. Andy has 60 toy cars. How many toy cars
does Ben have?
90 60
90 – 60 = 30
?
Multiplication- Jack has 3 boxes of cars. There are 8 cars in each box. How many cars
does Jack have?
? 8
8
8 x 3 = 24
8
Division- Marcus has 24 pieces of candy. He shares them equally with his 4 friends. How
many pieces of candy does each friend get? 24 ?
?
24 ÷ 4 = 6 ?
?
3rd Grade Teaching Strategies Two-Step Problem- The soccer club is going on a trip to the water park. The cost of
attending the trip is $63. Included in that price is $13 for lunch and the cost of 2 wristbands, one for the morning and one for the afternoon. Write an equation representing the cost of the field trip and determine the price of one wristband. w
w
13
63 3. Base Ten Models- use to model place value of the numbers in your problem.
Addition
Subtraction
4. Equal Groups (shares) - dividing a total number of objects into equal-sized groups. Sharing or grouping things into same sets. Multiplication- 3 flowers, 5 petals per flower 3 x 5 = 15 petals
Division- 12 stars, 3 groups 12÷ 3 = 4 stars per group
3rd Grade Teaching Strategies 5. Fact Families- four members are in each fact family. Use fact families to show relationships between addition & subtraction or multiplication & division. When adding, the greatest number is always the sum. When subtracting, the greatest number is always the minuend. 15 + 8 = 23
8 + 15 = 23
23 – 15 = 8
23 – 8 = 15
When multiplying, the greatest number is always the product. When dividing, the greatest number is always the dividend. 7 x 4 = 28
4 x 7 = 28
28 ÷ 7 = 4
28 ÷ 4 = 7
6. Number Bond - shows the relationship in a simple addition, subtraction, multiplication, or division problem. The number bond is based on the concept of “part-part-whole.” Addition + 25 = 65 + 3 = 68
43
4+3=7
3
40
43 + 25 = 68
Subtraction
75 -
= 70 – 3 = 67
8
10 –7 = ? 5
Multiplication: 7 x 8 = 56
3
75 – 8 = 67
Division: 36 ÷ 9 = ?
3rd Grade Teaching Strategies 7. Place Value - the value of a digit depending on its place in a number. Use place value to find the answers to addition, subtraction, and multiplication problems. Partial Sums
8. Repeated Addition- adding equal amounts until you find the product of a multiplication problem. Maria has 3 bags of apples. There are 2 apples in each bag. How many apples
does she have? Multiplication: 3 x 2 = 6 apples
Repeated Addition: 2 + 2 + 2 = 6 apples
9. Repeated Subtraction- subtracting equal amounts until you reach zero. Count the number of times you subtracted to find the quotient of a division problem. Charlie has 18
crayons. He shares them equally with 6 friends. How many crayons does each friend receive? Division: 18 ÷ 6 = 3 ? crayons
Repeated Subtraction: 18 – 6 – 6 – 6 = 0.
Since you subtracted 6 three times before you reached zero, the answer to the division problem is 3 crayons. 10. Rounding- changing a number to a more convenient value. Number Line
0-99 Chart
3rd Grade Teaching Strategies 11. Skip Counting (on a number line)- make equal jumps to solve problems. Multiplication: 3 x 5 = 15
three equal jumps forward from 0 on the number line to 15
Division: 18 ÷ 3 = 6- six equal jumps
backwards from 18 on the number line to 0
12. Skip Pattern Counting- when dividing by 2, 3, 5, or 10 skip pattern count by the divisor and stop when you reach the dividend. 21 ÷ 3 =
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
13. Time On A Number Line Diagram- number line diagrams can be used to solve problems involving elapsed time. Tony wakes up at 6:45 a.m. It takes him 5 minutes to shower, 15 minutes to get dressed, and 15 minutes to eat breakfast. What time will he be ready for school? 15
5
6:30
6:45
15
7:00
7:20
7:15
7:30
7:45
8:00
14. Traditional Algorithm- A set of predefined steps applicable to a class of problems that gives the correct result in every case when the steps are carried out correctly. Addition With and Without Regrouping
Subtraction With and Without Regrouping
+1
4 16
4 9 10
243
547
685
567
500
+ 436
+ 325
- 324
- 385
- 362
679
872
361
182
138
3rd Grade Teaching Strategies 15. Visual Fraction Model- A tape diagram, number line diagram, or area model. Area Models 1 4 1 4
1 4 1 4
1 4
1 4
Number Line
1 4
1 4
1/4 1/4 1/4 1/4
Use visual fraction models to determine if fractions are equivalent.
