Page 39 - SK Year 5 Mathematics DLP

11 7 815 × 21 = 21 is 20 and 1.
Multiply 7 815 by
Estimate the Calculate the actual answer. 20 and 1.
answer first. 1 1 Then, total up the

21 20 7 8 1 5 7 8 1 5 two products.
7 815 8 000 × 2 0 × 1
1 5 6 3 0 0 7 8 1 5
8 000 × 20 = 160 000
1 1
1 5 6 3 0 0
+ 7 8 1 5
1 6 4 1 1 5
164 115 is nearer to 160 000. The answer is reasonable.

7 815 × 21 = 164 115

12 4 025 × 83 =

R

S

Which calculation is
correct, R or S? Why?

3 0 7 0 × 2 =

What is the smallest digit in so that the product is a 6-digit number?

• Prepare stations for multiplication activities involving all methods 31
1.6.3 of multiplication. For examples, vertical form, lattice form, partition,
and estimation to reinforce pupils’ understanding.