I did this activity with my Year 2 class after we’d used (completed) multiplication grids to self-check answers to multiplication questions.
Children worked in pairs to take turns adding one number into the multiplication grid until it was complete. LOTS of opportunity to discuss what patterns they noticed or what approaches they took.
EXAMPLE: You can fill in the times tables going down as well as across.
The multiplication grid is like a mirror image running along the line of square numbers. Why is that do you think? (discuss commutativity of multiplication). This can be used to check if you have the right answers.
You can use repeated addition to find the answers to times tables you don’t know yet, eg 28 + 7 =35.
You can check your answer ‘fits’ or makes sense by looking at the other numbers around it to see if it fits the multiplication pattern. E.g 7, 14, 21, 18, 35, 42… You can tell 18 is wrong because it isn’t bigger than 21!
When children finish, draw their attention to square numbers. Why are they called square numbers do you think?
MASTERY EXTENSION QUESTIONS:
What three calculations were the hardest for you to answer? Why?
Which three did you find easiest to find the answer for? Why?
Choose 6 calculations and order them from hardest to easiest. Can you group your 6 calculations into just two groups? How did you decide to do it? Could you find different ways to group them?
Which times table do you find most challenging at the moment? How could you remember it do you think? Any tips or things you could spot to help you?
Choose a times table. Can you spot a pattern in it? Always odd or even? Ends with certain numbers?