2.3 To perform mental calculations

Mathematics

Multiplication

Educator section

Memorandum

Leaner section

Content

Activity: to perform mental calculations [lo 1.9.2]

1. Let us see if you still know your other tables. Something or someone is hidden away. Find the answers of the following and colour the blocks in.

When you have discovered what it is, write the answer down:

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1.1 9 x 4

1.2 6 x 7

1.3 5 x 9

1.4 12 x 6

1.5 7 x 9

1.6 3 x 8

1.7 6 x 9

1.8 11 x 12

1.9 8 x 7

1.10 12 x 8

1.11 7 x 5

1.12 6 x 8

1.13 12 x 12

1.14 9 x 8

1.15 12 x 9

15

DO YOU STILL REMEMBER?

10 = 10 x 1

100 = 10 x 10

1 000 = 10 x 10 x 10

10 000 = 10 x 10 x 10 x 10

100 000 = 10 x 10 x 10 x 10 x 10

1 000 000 = 10 x 10 x 10 x 10 x 10 x 10

DO YOU ALSO REMEMBER?

We can write the number in a shorter way by using the POWERS OF TEN.

10 = 101 (10 to the power of 1)

100 = 102 (10 to the power of 2)

1 000 = 103

10 000 = 104

100 000 = 105

1 000 000 = 106

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 involving:

1.9.2: multiplication of whole numbers to at least 12 x 12.