Page 84 - steps 4b 02.pdf

• Answers 4b • • • • • • • • • • • • • • • • • 3

DRM 21 DRM27
1 I , 3, 6, 10, 15, 21, 28, 36, 45, 55 I a 6174
triangular numbers b reverse number: 335q; answer: 6174
c digits indescending order: q863; reverse number: 368q;
2 17: I+ 6 + 10
answer: 6174
2q: I+ 28
31: 3 + 28 or I 0 + 21 or 6 + I 0 + 15 2 All the answers are the same.
46: Io + 36 or IO + 15 + 21 3 7743 takes 2 steps.
58: 3 + 55 or 15 + 15 + 28 or 3 + 1 0 + 45
q152 takes 5 steps.
67: 1 + 21 + 45 or 6 + 6 + 55 or 3 + 28 + 36 or I 0 + 21 + 36
q532 takes 6 steps.
3 All numbers between 1 O and 50 with the exception of:
10, 11, 13, 14, 16, 17, 20, 21, 32, 43, 44, 50

DRM22
1 A is 0·6 m long.
B is 0·86 m long.
C is 1 · 13 m long.
Dis 1·21 m long.
E is 1 ·45 m long.
F is 1 ·8q m long.
G is 2·07 m long.
2 difference between A and B: 0·26 m
difference between C and D: 0·08 m
A difference between E and F: 0·44 m
W 3 length of B and D: 2·07 m
length of E and G: 3·52 m
length of C and F: 3·02 m

DRM23
1 Open
2 a I 1 ·25 m b 375 cm c 13· 12 m d I ·88 m

DRM24
1 Ip: 20mm, 2cm Omm, 2·0cm
2p: 26 mm, 2 cm 6 mm, 2·6 cm
5p: 18mm, I cm 8mm, 1·8cm
1 Op: 24 mm, 2 cm 4 mm, 2·4 cm
£1: 22mm, 2cm 2mm, 2·2cm
2 20p:21mm,2cm 1mm,2·1 cm
50p: 30 mm, 3 cm O mm, 3·0 cm

3 Open
DRM25
1 round to nearest I 000 calculate check by adding
a 4000 - I 000 = 3000 2422 2422 + 1434 = 3856
b 5000 - 3000 = 2000 2217 2217 + 2657 = 4874
c 6000 - 2000 = 4000 4063 4063 + 1783 = 5846
d 3000 - 2000 = I 000 q11 q71 + 1705 = 2676
2 a 1742 b 2579 c 3288 DRM2Q
1 Open
DRM26 2 a kite, similar
1and2 b trapezium, similar
c quadrilateral, not similar

DRM30
Open

DRM31
a 14 x 6 = 84 b 1qxq=l7l
8 x 6 = 48 8 x q = 72
6x6=36 6 x q = 54
36 + 48 = 84 5 x q = 45
72 + 54 + 45 = 171

© HarperCollinsPub/ishers Ltd 1997 STEPS 4b Differentiation Pack