# Long Multiplication

Discussion in 'Mathematics' started by tennysonmash, Jan 15, 2012.

1. ### tennysonmash

I have to do a lesson on long multiplication as directed by the head of my department with a Year 9 class who are fairly high ability. I really do not know how to spin this out over a lesson so any extension ideas would be appreciated.
Thanks.

2. ### tennysonmash

I have to do a lesson on long multiplication as directed by the head of my department with a Year 9 class who are fairly high ability. I really do not know how to spin this out over a lesson so any extension ideas would be appreciated.
Thanks.

3. ### GoldMathsNew commenter

Possibly link it with algebra? And some proof?

Competition beat the clock maybe?

Computer Programming? Write the algorithm. How would you explain it to a 7 year old?

History of Multiplication? http://ualr.edu/lasmoller/medievalmult.html

4. ### MicheleChallenger

Try to link the long multiplication method to the grid method and discuss the advantages and disadvantages of each for different problems. Ask the class to choose with reasons the most efficient method for calculations such as:

19 x 24
160 x 52
25.7 x 0.6 etc

Then you could move on to (x+3)(x+4) using the grid method. The emphasis should be on the concept of multiplication and the various methods that may be used to perform it each with its own strengths and weaknesses for given situations. This includes mental arithmetic for calculations such as 75% of 120 etc.

5. ### googolplexOccasional commenter

Teach them long multiplication until they can do it, including problem solving situations. Then, do something else. If your kids are subsequently proficient in the topic, why spin it out? They should be moving on at this point.

6. ### PaulDGOccasional commenter

Decimals. Directed numbers.