objectives: make and justify estimates and approximations to calculations. use a calculator...
TRANSCRIPT
Objectives:
• Make and justify estimates and approximations to calculations.
• Use a calculator efficiently and effectively using BODMAS.
Vocabulary:
2.1 x 3.9 4.2 x 3.8 9.9 x 5. 2
31 x 49 2.99 x 4.11 19.9 x 20.1
10.01 x 99 2.7 x 5.3 9.9 x 9.1
Estimate the answer to each multiplication in the target board and find an answer to match in the ovals around the edges.
16 12
90 50
8 1000
15
400
1500
W/S 4.1B
2.1 x 3.9 4.2 x 3.8 9.9 x 5. 2
31 x 49 2.99 x 4.11 19.9 x 20.1
10.01 x 99 2.7 x 5.3 9.9 x 9.1
Answers:
16
12
90
508
1000 15
4001500
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.
1st 2nd 3rd
4 3 2 = 14
2 4 2 = 10
4 5 3 = 17
3 4 2 1 = 12
2 3 3 4 = 7
4 1 2 6 = 15
+
+
+ +
+
+
x
x
x
x
x
x
-
-
-W/S4.2B
4 3 2 = 14
2 4 2 = 10
4 5 3 = 17
3 4 2 1 = 12
2 3 3 4 = 7
4 1 2 6 = 15
+
+
+ +
+
+
x
x
x
x
x
x
-
-
-
M4.2(B)
Answers:
Remember the BODMAS rule to find the answers to the questions below.
( 3 + 2 ) x 4 =
3 x 2 + 7 =
( 4 + 3 ) x 3 =
2 x ( 3 - 1 ) =
3 + 4 x 2 - 1 =
17 x ( 5 - 4 ) =
M4.3B
Remember the BODMAS rule to find the answers to the questions below.
( 3 + 2 ) x 4 =
3 x 2 + 7 =
( 4 + 3 ) x 3 =
2 x ( 3 - 1 ) =
3 + 4 x 2 - 1 =
17 x ( 5 - 4 ) =
M4.3(B)
20
13
21
4
10
17
( 32 + 37 ) x 14 =
23 x 6 + 71 =
( 46 + 78 ) x 32 =
24 x ( 35 - 17 ) =
17 x ( 15 - 4. 8 ) =
17 + 43 x 6 - 7 =
M4.4B
( 32 + 37 ) x 14 =
23 x 6 + 71 =
( 46 + 78 ) x 32 =
24 x ( 35 - 17 ) =
17 x ( 15 - 4. 8 ) =
17 + 43 x 6 - 7 =
M4.4(B)
966
209
3968
432
268
173.4
For each of the questions below show clearly whether you used a mental, written or calculator method:
a. (7.3 + 2.7) x 4.3 b. 12 x 9 – 13 x 7
c. 38.4 ÷ (2.9 + 3.5) d. (2.7 + 8.5)² - 12.93
e. 4.2 + 6.4 x 8 f. 3.8² + 6
18 – 7 x 2 5²
g. 140.4 ÷ ( 4.8 + 2.6 + 1.5)
W/S4.5B
Answers:
a. (7.3 + 2.7) x 4.3 = 10 x 4.3 = 43
b. 12 x 9 – 13 x 7 = 108 – 91 = 17
c. 38.4 ÷ (2.9 + 3.5) = 6
d. (2.7 + 8.5)² - 12.93 = 112.51
e. 4.2 + 6.4 x 8 = 13.85
18 – 7 x 2
f. 3.8² + 6 = 0.8176
5²
g. 140.4 ÷ (4.8 + 2.6 + 1.5) = 15.775 (to 3 d.p.)
mentally
written
calculator
calculator
calculator
calculator
calculator
Objectives:
• Make and justify estimates and approximations to calculations.
• Use a calculator efficiently and effectively using BODMAS.
Vocabulary:
Thank you for your attention