Today, we are going to continue our learning of multiplication of 2 digits by 2 digits.
Have a look at the In focus question.
Zoom in on this picture and see if you can count how many seats there are.
Well done, there are 28 rows and each row has 26 seats. How can we use the grid method to solve this calculation?
Again, we are using our knowledge of partitioning the numbers and multiplying across.
This can get a little tricky so look carefully at the example. You must use your times tables and knowledge of multiplying by 10 , 100 and 1000 to solve some of these calculations.
Now, lets use the column method to solve the same question.
First, set the numbers out correctly like you would in a column method.
Next, multiply 8 and 6 which makes 48. Remember to exchange the 4 and add your 8 to the units column. Then, multiply the 6 by 2 and add 4 which makes 16. You should get 168 like it shows below.
In the final steps, you will now need to multiply the 2 in the bottom row to the 2 and 8 in the top row. Have a look below. 2 x 8 = 16 so we exchange the 1. Finally, multiply 2 and 2 and add 1 which makes 5.
Now, add together 168 and 56 which makes … 728!
You might want to look over that again as it is really tricky.
Here are two more ways of working out the same calculation. Which one do you prefer?
Try some of these questions using the methods we have learnt. Which method do you feel comfortable with?
Go through the calculation and use both methods to help you achieve an answer.
Did you get the answer 1989?
Complete worksheet 13 in your home learning book. Take a picture of your work and email it to your teacher through purple mash.
Q1 uses the grid method. Use partitioning, your knowledge of multiplying by 10 and 100 in some of the questions and column method to get your final answer.
Q2 uses the column method to multiply. Multiply, exchange and add to get your final answer.