To be able to do mental arithmetic

Mathematics

Number concept, addition and subtraction

Subtraction

Educator section

Memorandum

1.1 24

1.2 34

1.3 200

1.4 30

1.5 111

1.6 8

1.7 180

1.8 298

1.9 35

1.10 995

1.11 42

1.12 72

1.13 132

1.14 8

1.15 6

1.16 7

1.17 72

1.18 9

1.19 318

1.20 342

Leaner section

Content

Activity: to be able to do mental arithmetic [lo 1.9]

1. Before we look at more methods of subtraction, you have another chance to improve your mental arithmetic skills. Complete the following as quickly as you can.

1.1 38 – 14 = _________________

1.2 68 – 34 = _________________

1.3 _________________ – 101 = 99

1.4 110 – _________________ = 80

1.5 _________________ – 32 = 79

1.6 17 + _________________ = 25

1.7 260 + _________________ = 440

1.8 310 – 5 – 7 = _________________

1.9 400 – 15 – _________________ = 350

1.10 1 004 – 9 = _________________

1.11 6 × 7 = _________________

1.12 8 × 9 = _________________

1.13 12 × 11 = _________________

1.14 48 ÷ 6 = _________________

1.15 54 ÷ 9 = _________________

1.16 _________________ × 7 = 49

1.17 _________________ ÷ 6 = 12

1.18 81 ÷ _________________ = 9

1.19 Double 159: _________________

1.20 Halve 684: _________________

• Colour in the appropriate block:

My mental calculation marks have IMPROVED

Assessment

Learning Outcome 1: The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems.

Assessment Standard 1.9: We know this when the learner performs mental calculations.