ffirs.indd

Direct Multiplication 193
6 8
8 –1
57 –1 2
For the fi nal step we multiply the tens digits.
6 × 8 = 48
We add the 5 that was carried.
48 + 5 = 53
Th e answer is 5,372.
6 8
8 –1
53 57 –1 2
Test you rself
Try these for yourself:
a) 64 × 69 =
b) 34 × 78 =
Here are the answers:
a) 4,416 b) 2,652
Let’s work through the second problem together.
3 4
8 –2
26 25 –1 2
We begin by multiplying 4 times –2, which equals –8.
Borrowing 10, we have 2 left. We carry the –10 to the next
column as –1 (times 10).
Now we multiply crossways. Eight times 4 is 32, plus 3
times –2 is –6. Adding –6 is the same as subtracting 6