We are going to teach you what cubed numbers are...
Cubed numbers are when you times the number by itself and then by itself again. You might have already heard about squared numbers, which is one times less. For example 15 squared is 15 x 15.
Cubed numbers are multiplied by itself once more. For example, 15 cubed is 15 x 15 x 15. 15 cubed is not 15 x 3, it's very important you get that!
Today we worked together in little groups and had to decide what strategy was the best to use when we solved cubed numbers. We had to use multiplication strategies and addition/subtraction ones too.
Some of the strategies we used were
- PVP - Place Value Partitioning
- Compensating (Tidy numbers) and
- Doubling and halving
- Some of us tried using algorithms but we tried to use the other strategies instead.
We learnt that when you do cubed numbers, you have to solve them in two parts. Like 2 cubed = 2 x 2 x 2 and you work out the first bit which is 2 x 2 first which is 4, then times this answer by 2 again which is 8. You might see 2 cubed written with a normal 2 and then a little 3 on-top on the line after the normal number.
It was hard to solve the bigger cubed numbers like 11 cubed and 15 cubed, especially when we stretched ourselves to try other strategies.
We thought this maths lesson was pretty stretching and our brains had to work really hard but that's OK. We're excited to do more of this tomorrow and to keep pushing ourselves.
Do you know some of these strategies?