The document discusses strategies for teaching multiplication and division of whole numbers, emphasizing the importance of concrete visuals and expanded notation to help students understand computations. It includes examples of multiplying numbers in parts and showcases different solutions to multiplication problems using creative number combinations. Additionally, the use of number bonds is highlighted to aid students in developing their number sense when dealing with large numbers.

1. Session W8 Yeap Ban
Har
Whole Numbers www.banhar.blogspot.com

2. Learning & Reviewing
Basic Facts
Some ways to help students acquire and consolidate basic
facts.

3. 2x4=8
3x4=8+4

4. 2x4=8
4x4=8+8

5. 2x4=8
5 x 4 = 20
7 x 8 = 8 + 20

6. 10 x 4 = 40
9 x 4 = 40 – 4

8. Da Qiao Primary School, Singapore

9. She has 6. The product is
What do I 48.
have?

10. Multiplication & Division of
Large Numbers
Some ways to help students make sense of computation
algorithm

11. Find the value of 34 x 2
. 34
34 x2
x2 08
60 60
+8 68
68

12. Find the value of 34 x 3
. 34 34
x3 x3
90 12
12 90

13. The concrete and the visuals
help develop meaning i.e.
multiplying the tens and ones
separately.

14. 34
x3
90
12
The expanded notation
emphasizes 34 as 3 tens and
4 ones which are then dealt
with separately.

15. Quantities with different
‘nouns’ are dealt with
separately.

16. Find the value of 28 x 32 .
To see 28 as 20 and
8 and 32 as 30 and
2.
This leads to the
idea of (a + b)(c +
d).

18. x
Use the digits 0 to 9 no more than once
to make a correct multiplication
sentence.
The class had four solutions
32 x 15 = 480
12 x 65 = 780
12 x 48 = 576
39 x 12 = 468
12 x 43 did not work.

19. 12 can be seen as 10 and 2.
Thus, 12 x 65 can also be computed as the sum of 10 x 65 and 2
x 65 i.e. 650 + 130.
12 can be seen as 10 and 2.
Thus, 39 x 12 can also be computed as the sum of 39 x 10 and
39 x 2 i.e. 390 + 78.
Alternatively, 40 x 12 can be used to compute 39 x 12.
The use of number bonds to compute large numbers gives
students opportunities to develop their number sense.

20. Find the value of 7081 3.
Using number bonds, 7081 is
6000, 900, 180 and 1. Each is
then divided by three.