1. Level 4/5 Booster
Lesson 4B
Using a Calculator

2. enter memory calculator display Objectives:
Make and justify estimates and approximations to calculations.
Use a calculator efficiently and effectively using BODMAS.
Vocabulary:
enter
memory
calculator display

3. W/S 4.1B
Estimate the answer to each multiplication in the target board and find an answer to match in the ovals around the edges. 16 12
2.1 x 3.9
4.2 x 3.8
9.9 x 5. 2 8
31 x 49
2.99 x 4.11
19.9 x 20.1
1000
10.01 x 99
2.7 x 5.3
9.9 x 9.1 15
1500 90
400 50

4. Answers:
2.1 x 3.9
4.2 x 3.8
9.9 x 5. 2 16 50 8
31 x 49
2.99 x 4.11
19.9 x 20.1 12
400
1500
10.01 x 99
2.7 x 5.3
9.9 x 9.1 15
1000 90

5. Identify the order of the operations in the equations below – colour the operation (+ - x or ÷) box as given in the key.
1st
2nd
3rd
Example: 4 + 2 x 5 = 14 4 + 2 x 5 = 14 4 + 2 x 5 = 14
Remember BODMAS rule.

6. 1st
3rd
2nd
= 14 x +
= 10 + x
= 17 - x
= 12 + x +
= 7 + x -
= 15 - + x
W/S4.2B

7. Answers:
= 14 x +
= 10 + x
= 17 - x
= 12 + x +
= 7 + x -
= 15 - + x
M4.2(B)

8. Remember the BODMAS rule to find the answers to the questions below.
( ) x 4 =
3 x =
( ) x 3 =
2 x ( ) =
x =
17 x ( ) =
M4.3B

9. Remember the BODMAS rule to find the answers to the questions below.
( ) x 4 = 20
3 x = 13
( ) x 3 = 21
2 x ( ) = 4
x = 10
17 x ( ) = 17
M4.3(B)

10. ( ) x 14 =
23 x =
( ) x 32 =
24 x ( ) =
x =
17 x ( ) =
M4.4B

11. ( ) x 14 =
966
209
23 x =
( ) x 32 =
3968
24 x ( ) =
432
x =
268
17 x ( ) =
173.4
M4.4(B)

12. For each of the questions below show clearly whether you used a mental, written or calculator method:
( ) x 4.3 b. 12 x 9 – 13 x 7
c ÷ ( ) d. ( )²
x 8 f. 3.8² + 6
18 – 7 x ²
g ÷ ( )
W/S4.5B

13. Answers:
( ) x 4.3 = 10 x 4.3 = 43
12 x 9 – 13 x 7 = 108 – 91 = 17
38.4 ÷ ( ) = 6
( )² =
x 8 = 13.85
18 – 7 x 2
f. 3.8² = 5²
g ÷ ( ) = (to 3 d.p.)
mentally
written
calculator
calculator
calculator
calculator
calculator

14. enter memory calculator display Objectives:
Make and justify estimates and approximations to calculations.
Use a calculator efficiently and effectively using BODMAS.
Vocabulary:
enter
memory
calculator display

15. Thank you for your attention