Adding & Subtracting Decimals — Worksheet & Memo

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Grade 8 · Decimal Fractions

Adding & Subtracting Decimals

EXAM-STYLE CLASS TEST

Marks

Duration

50 minutes

Questions

Name:

Class:

Date:

Mark

/ 33

Instructions and Information

Answer ALL the questions in this question paper.
Answer QUESTION 1 by circling the letter (A–D) in the answer grid at the end of that section.
Show ALL calculations clearly.
Show all units where applicable.
Number the answers correctly according to the numbering system used in this question paper.
A non-programmable calculator may be used, unless stated otherwise.
Write neatly and legibly.

Question 1

[10 MARKS]

Four options are given as possible answers to the following questions. Choose the correct answer and circle the letter (A–D) in the grid at the end of this section. If you want to change your choice, put a cross through the wrong letter and circle your new choice.

1.1
3,4 + 12,75 = …
(1)
A)16,15
B)4,675
C)15,15
D)16,79
1.2
20 − 6,45 = …
(1)
A)14,55
B)13,55
C)14,45
D)26,45
1.3
When adding decimals you must line up the …
(1)
A)last digits
B)commas
C)first digits
D)longest numbers
1.4
A pipe 2,5 m long has 0,85 m cut off. The piece left is …
(1)
A)1,65 m
B)2,35 m
C)1,75 m
D)3,35 m
1.5
0,7 + 0,3 = …
(1)
A)0,10
B)1
C)0,1
D)0,21
1.6
Thandi buys items for R12,60, R8,45 and R23,95. Her total is …
(1)
A)R44,00
B)R45,00
C)R43,90
D)R45,10
1.7
Which one of the following is CLOSEST to 1?
(1)
A)0,89
B)0,98
C)1,2
D)0,9
1.8
She pays with R50 for goods costing R38,75. Her change is …
(1)
A)R12,25
B)R11,25
C)R12,75
D)R11,35
1.9
6,08 + 0,9 = …
(1)
A)6,17
B)6,98
C)7,08
D)6,89
1.10
Which calculation gives an answer of exactly 5?
(1)
A)4,5 + 0,4
B)3,75 + 1,25
C)2,8 + 2,3
D)1,95 + 3,15

Answer grid — circle your answers for Question 1

1.1	A	B	C	D
1.2	A	B	C	D
1.3	A	B	C	D
1.4	A	B	C	D
1.5	A	B	C	D
1.6	A	B	C	D
1.7	A	B	C	D
1.8	A	B	C	D
1.9	A	B	C	D
1.10	A	B	C	D

Question 2

[11 MARKS]

Calculate the following WITHOUT using a calculator. Show ALL your working.

2.1
20 − 6,45 − 2,8
(4)
2.2
(4,6 + 2,35) × 0,2
(4)
2.3
Estimate 19,7 + 4,2 by rounding each number to the nearest whole number, then give the exact answer.
(3)

Question 3

[12 MARKS]

Ann buys three items at a shop: R32,40, R15,85 and R9,99. She pays with a R100 note.

3.1
Calculate the total cost of the three items.
(3)
3.2
Calculate the change Ann receives.
(3)
3.3
A plank is 2,4 m long. A piece of 0,85 m and a piece of 0,6 m are cut off. Calculate the length of the plank that is left.
(4)
3.4
Explain why the decimal commas must be lined up before adding.
(2)

TOTAL: 33 marks

This question paper consists of 3 questions.