Rainbow Method🌈

IALA: how to use Rainbow Method to solve multiplication problems.

Last week on Friday we had a substitute. Our substitute teacher was called Mr Tafea.

Mr Tafea was a really cool teacher. He taught us 4 different strategies to work multiplication problems. The names of the strategies are Rainbow , Lattice , Lines and Algorithm method. All of these strategies are efficient but I am going to only teach you how to use the Rainbow Method. If you want to see my explanation how to use the lines method click HERE  

Now here is how to use the Rainbow Method.

21 x 31

First you multiply the numbers in the front.

Which will be 2 x 3 = 6 . After that you leave a blank space.

2 x 3 = 6_

Next you need to multiply the numbers at the back.

Which will make 1 x 1 = 1.

Then you add the 1 to your answer. Now it will look like 6_1.

To get the answer in the middle you need to multiply the numbers that you haven't multiplied in the beginning. So (2 x 1) + (3x1) = 5.

Next you add the 5 to your answer.

21 x 31 = 651

That is your answer.