1. 62; 63

2.1 9

2.2 132

2.3 17

2.4 331

2.5 498

2.6 68.5

2.7 1 000

2.8 144

2.9 +

2.10 10

2.11 63

2.12 176

2.13 7

2.14 4

2.15 450

1. See how many figures you can find in this garden and then add them together. If you work cleverly you will be able to calculate the answers in a flash! Are you able to see how?

What is your answer? __________________________________________________

2. Now we are going to test your mental calculation skills in a different way. If you know your multiplication tables and can also add and subtract well, you will not have any trouble. Try to complete these within three minutes:

2.1 ___________ x 8 = 72

2.2 ___________ ÷ 11 = 12

2.3 119 + ____________ = 136

2.4 _____________ - 214 = 117

2.5 Double 249: _________________

2.6 Halve 137: __________________

2.7 30 x _______________ = 30 000

2.8 4 x 3 x 12 = _______________

2.9 567 ______________ 23 = 590

2.10 8 670 ÷ _____________ = 867

2.11 (5 x 9) + 18 = _____________

2.12 (7 + 15) x 8 = ______________

2.13 (42 ÷ ___________) + 14 = 20

2.14 (5 x ______________) – 9 = 11

2.15 Halve x _________________ = 225

Complete by colouring in the appropriate block:

I did | WELL | AVERAGE | POORLY |

The answer to an addition sum is called the SUM.

Thus: 4 873 + 2 168 = 7 041

addend addend sum

3. Some more mental calculation!

Calculate the answers without using a calculator. Use the code and complete the following sentence:

Subtraction is called the _____________________________________ of addition.

3.1 27 + 35

3.2 48 + 16

3.3 53 + 19

3.4 23 + 37

3.5 39 + 17

3.6 15 + 24

3.7 26 + 34

I | A | N | K | V | O | E |

62 | 74 | 64 | 102 | 72 | 88 | 60 |

B | R | Y | S | P | M | T |

31 | 56 | 20 | 39 | 99 | 52 | 32 |

We can also say that subtraction is the in**verse operation **of addition. I can test an addition sum by subtracting.

* 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 involving:

**1.9.1:** addition and subtraction.