1. Created by Mr. Lafferty Maths Dept.
Whole Numbers
MNU 2-02a
MNU 2-03a
Multiplying & Dividing by 10,100,1000
Multiplying by a Single Digit
Dividing by a Single Digit
Multiplying & Dividing by 20, 300 etc..
Rounding to nearest 10,100,1000
Estimating Answers
8-Sep-18
Created by Mr. Lafferty Maths Dept.

2. Created by Mr. Lafferty Maths Dept.
Starter Questions
MNU 2-02a
MNU 2-03a
34o
8-Sep-18
Created by Mr. Lafferty Maths Dept.

3. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiply by 10, 100, 1000
MNU 2-02a
MNU 2-03a
Learning Intention
Success Criteria
1. To understand how to multiply and divide simple whole numbers by 10, 100, 1000.
Understand the simple rules to multiply and divide simple whole numbers.
2. Be able do simple calculations.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

4. Whole Numbers www.mathsrevision.com Multiply by 10, 100, 1000
MNU 2-02a
MNU 2-03a
For this section you need to know your tables
To multiply by 10, 100, 1000
To multiply by 10 simply add a zero to the number
To multiply by 100 simply add 2 zero’s to the number
To multiply by 1000 simply add 3 zero’s to the number
Example : Multiply 36 by 10, 100, 1000.
Guess rule for 1000
36 x 10 =
360
36 x 100 =
3600
36 x 1000 =
36000
8-Sep-18
Created by Mr. Lafferty Maths Dept.

5. Whole Numbers www.mathsrevision.com Multiply by 10, 100, 1000
MNU 2-02a
MNU 2-03a
Example : A box of crisps contain 48 packets.
How many in 100 boxes ?
48 x 100 =
4800
8-Sep-18
Created by Mr. Lafferty Maths Dept.

6. Whole Numbers www.mathsrevision.com Divide by 10, 100, 1000
MNU 2-02a
MNU 2-03a
Try and write down rule for 100, 1000
To Divide by 10, 100, 1000
To divide by 10 remove a zero from the number
To divide by 100 remove 2 zero’s from the number
To divide by 1000 remove 3 zero’s from the number
Example : Divide by 10, 100, 1000.
54000÷ 10 =
5400
54000 ÷ 100 =
540
54000 ÷ 1000 = 54
8-Sep-18
Created by Mr. Lafferty Maths Dept.

7. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Divide by 10, 100, 1000
MNU 2-02a
MNU 2-03a
Example : A box contains 1000 cups. How many boxes are needed to hold 7000 ?
7000 ÷ 1000 = 7
8-Sep-18
Created by Mr. Lafferty Maths Dept.

8. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiply & Divide by 10, 100, 1000
MNU 2-02a
MNU 2-03a
Now try
Exercise 3 & 4
Ch1 (page 13)
8-Sep-18
Created by Mr. Lafferty Maths Dept.

9. Created by Mr. Lafferty Maths Dept.
Starter Questions
MNU 2-02a
MNU 2-03a
34o
8-Sep-18
Created by Mr. Lafferty Maths Dept.

10. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiplying by a single number
MNU 2-02a
MNU 2-03a
Learning Intention
Success Criteria
1. To show how to do multiply by a single digit.
To know your tables.
2. To show appropriate layout and working for multiplying by a single digit.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

11. Whole Numbers www.mathsrevision.com Multiplying by a single number
MNU 2-02a
MNU 2-03a
To be able to multiply by a single digit you need to
know your tables.
Examples
8-Sep-18
Created by Mr. Lafferty Maths Dept.

12. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiplying by a single number
MNU 2-02a
MNU 2-03a
Example : A palette holds 164 tins of paint.
How many tins in 8 palettes.
164 x8
1312 53
8-Sep-18
Created by Mr. Lafferty Maths Dept.

13. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiplying by a single number
MNU 2-02a
MNU 2-03a
Now try Exercise 5
Ch1 (page 15)
8-Sep-18
Created by Mr. Lafferty Maths Dept.

14. Created by Mr. Lafferty Maths Dept.
Starter Questions
MNU 2-02a
MNU 2-03a
123o
8-Sep-18
Created by Mr. Lafferty Maths Dept.

15. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Dividing by a single number
MNU 2-02a
MNU 2-03a
Learning Intention
Success Criteria
1. To show how to do divide by a single digit.
1. To show appropriate layout and working for dividing by a single digit.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

16. Whole Numbers www.mathsrevision.com Dividing by a single number
MNU 2-02a
MNU 2-03a
Use the following layout for dividing by a single digit.
Examples
8-Sep-18
Created by Mr. Lafferty Maths Dept.

17. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Dividing by a single number
MNU 2-02a
MNU 2-03a
Example : A carton can hold 6 eggs.
How many cartons are needed
for 5436 eggs.
906
5436 6
8-Sep-18
Created by Mr. Lafferty Maths Dept.

18. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Dividing by a single number
MNU 2-02a
MNU 2-03a
Example : Copy and complete.
544
1853
1239
3808 7
9265 5
7434 6
652
952
2336
5216 8
3808 4
7008 3
8-Sep-18
Created by Mr. Lafferty Maths Dept.

19. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Dividing by a single number
MNU 2-02a
MNU 2-03a
Now try Exercise 7
Ch1 (page 17)
8-Sep-18
Created by Mr. Lafferty Maths Dept.

20. Created by Mr. Lafferty Maths Dept.
Starter Questions
MNU 2-02a
MNU 2-03a
36o
8-Sep-18
Created by Mr. Lafferty Maths Dept.

21. Created by Mr. Lafferty Maths Dept.
Whole Numbers
MNU 2-02a
MNU 2-03a
Multiply or Divide by 20,300,4000
Learning Intention
Success Criteria
1. Understand the two step process to multiply or divide by 20, 300 etc…
1. To explain how to divide by 20, 300, 4000 etc using our knowledge so far.
2. Show all working.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

22. Whole Numbers www.mathsrevision.com
Multiply or Divide by 20,300,4000
MNU 2-02a
MNU 2-03a
By combining our knowledge so far of
“multiplying / dividing by 10, 100, 1000”
and
“multiplying / dividing by a single digit”
we can do harder calculations.
We use a TWO step process.
Example 1 : Calculate 20 x 52
20 can be written as 2 x 10 so we have :
2 x 10 x 52 =
Step 1 : 10 x 52 =
520
Step 2 : 2 x 520 =
1040
8-Sep-18
Created by Mr. Lafferty Maths Dept.

23. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiply or Divide by 20,300,4000
MNU 2-02a
MNU 2-03a
Example 2 : Calculate 44 x 30
30 can be written as 10 x 3 so we have :
44 x 10 x 3 =
Step 1 : 44 x 10 =
440
Step 2 : 440 x 3 =
1320
Example 3 : Calculate 300 x 35
300 can be written as 3 x 100 so we have :
3 x 100 x 35 =
Step 1 : 100 x35 =
3500
Step 2 : 3500 x 3 =
10500
8-Sep-18
Created by Mr. Lafferty Maths Dept.

24. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiply or Divide by 20,300,4000
MNU 2-02a
MNU 2-03a
Example 4 : Calculate ÷ 200
Since 200 divide by 100 then divide by 2:
16000 ÷ 100 ÷ 2 =
160
Step 1 : ÷ 100 = 80
Step 2 : 160 ÷ 2 =
8-Sep-18
Created by Mr. Lafferty Maths Dept.

25. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Multiply or Divide by 20,300,4000
MNU 2-02a
MNU 2-03a
Example 5 : Calculate ÷ 6000
Since 6000 divide by 1000 then divide by 6:
÷ 1000 ÷ 6 =
120
Step 1 : ÷ = 20
Step 2 : 120 ÷ 6 =
8-Sep-18
Created by Mr. Lafferty Maths Dept.

26. Created by Mr. Lafferty Maths Dept.
Whole Numbers
MNU 2-02a
MNU 2-03a
Multiply or Divide by 20,300,4000
Now try Exercise 8
Ch41 (page 19)
8-Sep-18
Created by Mr. Lafferty Maths Dept.

27. Created by Mr. Lafferty Maths Dept.
Starter Questions
MNU 2-02a
MNU 2-03a
28o
8-Sep-18
Created by Mr. Lafferty Maths Dept.

28. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Rounding to nearest 10, 100 and 1000
MNU 2-02a
MNU 2-03a
Learning Intention
Success Criteria
1. Understand the rules for rounding to the nearest 10, 100, 1000.
1. To round numbers to the nearest 10, 100 and 1000.
2. Apply rules to problems.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

29. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Rounding to nearest 10, 100 and 1000
MNU 2-02a
MNU 2-03a
To round to the nearest 10 : look at the units digit:
- If it is a 0, 1, 2, 3, 4 leave the 10’s digit as it is.
- If it is a 5, 6, 7, 8, 9 round the 10’s digit up by 1.
To round to the nearest 100 : look at the tens digit:
- If it is a 0, 1, 2, 3, 4 leave the 100’s digit as it is.
- If it is a 5, 6, 7, 8, 9 round the 100’s digit up by 1.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

30. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Rounding to nearest 10, 100 and 1000
MNU 2-02a
MNU 2-03a
To round to the nearest 1000 : look at the hundreds digit:
- If it is a 0, 1, 2, 3, 4 leave the 1000’s digit as it is.
- If it is a 5, 6, 7, 8, 9 round the 1000’s digit up by 1.
Example : Round 3467 to the nearest 10, 100, 1000
The nearest 10 : 3467
3470
- look at the units digit :
The nearest 100 : 3467
3500
- look at the tens digit :
The nearest 1000 :3467
3000
- look at the hundreds digit:
8-Sep-18
Created by Mr. Lafferty Maths Dept.

31. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Rounding to nearest 10, 100 and 1000
MNU 2-02a
MNU 2-03a
Example : Round to the nearest 10, 100, 1000
The nearest 10 :
- look at the units digit :
18 570
The nearest 100 :
- look at the tens digit :
18 600
The nearest 1000 :18565
- look at the hundreds digit:
19 000
8-Sep-18
Created by Mr. Lafferty Maths Dept.

32. Created by Mr. Lafferty Maths Dept.
Whole Numbers
Rounding to nearest 10, 100 and 1000
MNU 2-02a
MNU 2-03a
Now try Exercise 9
Ch1 (page 21)
8-Sep-18
Created by Mr. Lafferty Maths Dept.

33. Created by Mr. Lafferty Maths Dept.
Starter Questions
MNU 2-02a
MNU 2-03a
42o
8-Sep-18
Created by Mr. Lafferty Maths Dept.

34. Created by Mr. Lafferty Maths Dept.
Whole Numbers
MNU 2-02a
MNU 2-03a
Using Rounding to Estimate Answers
Learning Intention
Success Criteria
1. Be able to round numbers to a whole number.
1. To explain how estimate answer by rounding a number to an easier number for mental calculation
2. Estimate the answer to a difficult calculation using easier whole numbers.
8-Sep-18
Created by Mr. Lafferty Maths Dept.

35. Whole Numbers www.mathsrevision.com 40 x 50 = 400 x 5 = 2000
MNU 2-02a
MNU 2-03a
Using Rounding to Estimate Answers
It is very important when solving problems that we have
a rough idea of the answer we are expecting.
Example : Mentally estimate the answer to 42 x 49
Easiest way, is to round the two numbers first
40 x 50 =
400 x 5 =
2000
8-Sep-18
Created by Mr. Lafferty Maths Dept.

36. Created by Mr. Lafferty Maths Dept.
Whole Numbers
MNU 2-02a
MNU 2-03a
Using Rounding to Estimate Answers
Example : Mentally estimate the answer to 104 x 19
Easiest way, is to round the two numbers first
100 x 20 =
1000 x 2 =
2000
Example : Mentally estimate the answer to 878 ÷ 27
Easiest way, is to round the two numbers first
900 ÷ 30 =
90 ÷ 3 = 30
8-Sep-18
Created by Mr. Lafferty Maths Dept.

37. Created by Mr. Lafferty Maths Dept.
Whole Numbers
MNU 2-02a
MNU 2-03a
Using Rounding to Estimate Answers
Now try Exercise 10
Ch1 (page 22)
8-Sep-18
Created by Mr. Lafferty Maths Dept.