What I mean by this is, say for example you were asked to multiply:



You probably know that this is 100, but let’s look at a trick to be able to work out any sum like this. Staying with this example:


Step 1: move the “0” from each number to one side, but remember that you’ve done this. 



Now you’re left with:



Step 2: How many “0” did you move to one side? – well you moved one from each number 10, so you moved two altogether. So…. put the two “0” back.


This is your answer, and it works very well all of the time. 



Let’s look at a tougher example:



Step 1: move the two “0” out of the way:



Step 2: use the table above to find the value for 15 x 5:



Step 3: put the two “0” back:



Once you have mastered the times tables, you will be able to do any question like this.


Here’s another example:



Step 1: move the FOUR “0” out of the way:



Step 2: use the table to find out 17 x 7 (this is 119):



Step 3: put the FOUR “0” back:




So “one hundred and seventy times seven thousand” = “one million, one hundred and ninety thousand”:


Examples: Try these yourself



















Write your answer like this: 60 x 30 = 6 x 3 (00) = 18(00) = 1800


Self Test Answers:


30 x 40

1200

60 x 90

5400

50 x 80

4000

30 x 120

3600

140 x 90

12600

260 x 50

1300

340 x 40

13600

500 x 20

10000

700 x 700

490000

240 x 120

28800

360 x 120

43200

480 x 20

9600

10 x 2000

20000

3000 x 50

150000

200 x 5600

1120000

4500 x 2300

10350000