Page 158 - SK Year 5 Mathematics DLP

The number of rings on the
4 Estimate the age, in centuries,
cross-section of tree A indicates
of tree B. that tree A is about 0.2 century old.
0.2 century + 0.3 century = century
Cross-section
0.2 century of tree A
+ 0.3 century
0.5 century
Cross-section
0.2 century + 0.3 century = 0.5 century of tree B

The estimated age of tree B is about Tree B is 0.3 century older
0.5 century. than tree A.

5 12.6 centuries + 58 decades = centuries decades
century decade
12.6 centuries = 12 centuries + 0.6 century 1
1 2 6
= 12 centuries + (0.6 × 10) decades
+ 5 8
= 12 centuries 6 decades
1 2 6 4
+ 6 − 6 0
1 8 4

12.6 centuries + 58 decades = 18 centuries 4 decades

9
6 Add 4 centuries and 3.2 centuries. Give the answer in centuries
10
and decades.
9
4 centuries + 3.2 centuries = centuries decade
10
9
9 9 4 centuries = 4 centuries 9 decades.
century = ( × 10) decades 10
10 10 3.2 centuries = 3 centuries 2 decades.
= 9 decades
century decade
4 9
0.2 century = (0.2 × 10) decades
+ 3 2
= 2 decades 7 1 1

+ 1 − 1 0
8 1

9
4 centuries + 3.2 centuries = 8 centuries 1 decade
10

150 4.3.1 (v) • Provide more exercises on constructing number sentences orally
4.3.2 (v) using flash cards.
• Surf https://rb.gy/rfusfb