Video Transcript
What are the missing numbers in the
given sequence?
In this question, we’re given a
number line. But unfortunately, this number line
has got two missing numbers on it. Can you work out what they are? Let’s look at our first missing
number to begin with. Now, one of the ways that we can
find a missing number on a number line is to look at the scale of the number line,
in other words, how the numbers change. But another way that we can find
numbers is to think about the numbers either side of our missing number.
In this example, we can see that
our missing number is exactly halfway between the numbers 300 and 400. Now, let’s imagine that we’ve got a
really strong magnifying glass and we can zoom in just on this little part of the
number line. It would look like this, wouldn’t
it? Now, what number comes halfway
between 300 and 400? It’s 350. This means that the scale of our
number line or, in other words, the amount that we add each time is 50. Each new number is 50 more than the
last. So if we look at our second missing
number, we can use this idea of counting in 50s to help us.
Let’s start from the number
500. 500, 550, what, 650. What number is 50 more than
550? It’s 600. Let’s read our way along the whole
number line and see whether our two missing numbers fit in. 200, 250, 300, 350, 400, 450, 500,
550, 600, 650, 700, 750, 800. The missing numbers in this
sequence are 350 and 600.
