In this video
As with ALL my videos...
Here, the Area = 32cm squared
We have to find the width.
We can solve this problem
using our Tables knowledge
The question I ask myself is:
4 x what number = 32?
Use your 4x table knowledge
8cm is the missing side length
Do you see?
Knowing your multiplication tables
can help you get straight to the answer
If you haven't learned your tables yet...
It's TIME! You NEED this.
As you know:
In this rectangle
we have a side measuring 2cm
and an Area...
2 x some number = 28
28 is NOT in our 2x table knowledge.
28 ÷ 2 = length of missing side
How many twos in 2?
How many twos in 8?
That wasn't too tricky!
Yes, the Area value was outside
our 2x table knowledge
but it worked out perfectly,
with NO remainder!
But... You've guessed it!
Last example:
If you know your 4x table,
you know that 38 is NOT in it!
We know:
Put the 9 on the answer line
and there's a remainder of 2
I'm working out a measurement for my diagram
so if I just write 'remainder 2'...
I need to show parts of a centimetre.
To show the remainder in decimal form
we put a decimal point HERE
in the dividend
And a matching one on the answer line.
And a zero to work with, in the dividend, too!
Ok. We know that 38 ÷ 4 = 9 r2
And now, we can put that remainder in place.
Now: how many fours are there in 20?
Of course, you know:
There's NO remainder,
so we're all done!
The missing side = 9.5cm
And of course:
Have fun with this
See you soon on Let's Do Math!