1.2.1 Directed Numbers, PT3 Practice


1.2.1 Directed Numbers, PT3 Practice 1
Question 1:
Complete the following calculation.
4.6 × ( 3 5 1 3 4 ) = 4.6 × ( 0.6 x ) = 4.6 × x = x

Solution:
4.6 × ( 3 5 1 3 4 ) = 4.6 × ( 0.6 1.75 ) = 4.6 × 1.15 = 5.29


Question 2:
Complete the following calculation.
43 + 35 ÷ 1 1 6 = 43 + 35 ÷ 7 6 = 43 + 35 × x = 43 + x = 13

Solution:
43 + 35 ÷ 1 1 6 = 43 + 35 ÷ 7 6 = 43 + 35 × 6 7 = 43 + 30 = 13



Question 3:
Calculate each of the following.
  (a) (–9) × 14
  (b)   6.7 – 3.2 × (–0.5)  
  (c) –144 ÷ (–8) ÷ (–2)   

Solution:
 (a) (–9) × 14 = –126
 (b)   6.7 – 3.2 × (–0.5) = 6.7 – (–1.6)
= 6.7 + 1.6
 = 8.3
 (c) –144 ÷ (–8) ÷ (–2) = –144 ÷ 4
= 36


Question 4:
Calculate the value of
0.6 + ( 1 2 3 ) ÷ ( 4 15 ) 2

Solution:
0.6 + ( 1 2 3 ) ÷ ( 4 15 ) 2 = 0.6 + [ 5 3 × 15 5 4 ] 2 = 0.6 + [ 25 4 ] 2 = 0.6 6 1 4 2 = 0.6 6.25 2 = 7.65



Question 5:
Calculate the value of
( 0.6 × 1 1 4 ) [ 1.6 × ( 1.5 ) ] ÷ 0.4

Solution:
( 0.6 × 1 1 4 ) [ 1.6 × ( 1.5 ) ] ÷ 0.4 = ( 0.6 0.3 × 5 4 2 ) [ 1.6 4 × ( 1.5 ) 0.4 1 ] = 1.5 2 6 = 0.75 6 = 6.75