MATHEMATICS

Estimations, Equations and Variables

EDUCATOR SECTION

Memorandum

4. Own attempts

5. (a) 202

(b) 485

(c) 8

(d) 8

(e)` 7

(f) 56

(g) 820

(h) 96

(i) 470

(j) 18 400

(k) 40

(l) 64

(m) 10 000

(n) 64

(o) 1 000 000

Leaner Section

Content

ACTIVITY: Estimations, Equations and Variables (Mental calculation test) [LO 1.7.2, LO 1.7.7, LO 1.8, LO 1.10]

4. Brainteaser!

Can you form a square / rectangle / triangle with the following seven tangram pieces?

Figure 1

5. Let's first see how you cope with "ordinary" numbers!

Complete the following mental calculation test as quickly and accurately as possible:

a) 179 + 23 = _______________

b) 512 – 27 = _______________

c) 9 x _______________ = 72

d) _______________ x 6 = 48

e) 63 ÷ 9 = _______________

f) _______________ ÷ 8 = 7

g) 24 600 ÷ 30 = _______________

h) (60 ÷ 5) x (32 ÷ 4) = _______________

i) 3 x 47 + 7 x 47 = _______________

j) 25 x 184 x 4 = _______________

k) 158 – 130 + 12 = _______________

l) 82 = _______________

m) 1002 = _______________

n) 43 = _______________

o) 1003 = _______________.......

15

Complete by colouring in the appropriate block:

I have performed

Table 1

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 1.7: We know this when the learner estimates and calculates by selecting and using operations appropriate to solving problems that involve:

1.7.2: multiple operations with integers;

1.7.7: exponents.

Assessment Standard 1.8: We know this when the learner performs mental calculations involving squares of natural numbers to at least 10² and cubes of natural numbers to at least 5³;

Assessment Standard 1.10: We know this when the learner uses a range of strategies to check solutions and judges the reasonableness of solutions.