Numbers Above the Reference Number 25
MULTIPLYING NUMBERS ABOVE 100
We can use our speed math method to multiply numbers above 100
as well. Let’s try 113 times 102.
We use 100 as our reference number.
+13
+2
100 113 × 102 =
Add crossways:
113 + 2 = 115
Multiply by the reference number:
115 × 100 = 11,500
Now multiply the numbers in the circles:
2 × 13 = 26
Th is is how the completed problem looks:
+13
+2
100 113 × 102 = 11,500
- 26
11,526 Answer
SOLVING PROBLEMS IN YOUR HEAD
When you use these strategies, what you say inside your head is
very important, and can help you solve problems more quickly and
easily.
Let’s try multiplying 16 by 16.