Video Transcript
Complete the pattern: 433, 383,
333, what, what, what.
In this question, we’re given a
pattern. And we have to complete the three
missing numbers. Before we can find the missing
numbers, we need to work out the rule of the pattern. The first thing you might notice
about these numbers is that they are decreasing. They’re going down in value. 433, 383, 333. We know the numbers are decreasing,
but we have to work out by how much. How do we get from 433 to 383? To find the difference, we could
subtract. We can take 383 from 433. That will tell us how much the
number has decreased by.
We know that three ones take away
three ones leaves us with zero. We’ve got three 10s. We need to subtract eight. So we need to exchange. We can take 100 and exchange it for
10 10s, which is 13 take away eight. 13 10s take away eight 10s leaves
us with five 10s. And three 100s take away three 100s
leaves us with no hundreds. So the difference between 433 and
383 is 50. We have to subtract 50. And to make sure that the rule is
subtract 50, let’s find the difference between 383 and 333. Again, we’ve got three ones and we
need to take away three ones, which leaves us with no ones. Eight 10s take away three 10s
leaves us with five 10s. And three 100s subtract three 100s
leaves us with no hundreds. The difference is 50.
So to find the next number in the
sequence, we need to subtract 50 from 333. Three take away zero is three. Three 10s are less than five 10s,
so we need to exchange. 13 10s take away five 10s leaves us
with eight 10s. And two 100s take away nothing
leaves us with two 100s. So the first of our missing numbers
is 283. So what’s 283 subtract 50? Did you notice the pattern in the
tens and ones digits? 33, 83, 33, 83. 283 subtract 50 is 233. To find the last number in the
pattern, we need to take 50 away from 233. Can you predict what the number
will be? 433, 383, 333, 283, 233, 183. The missing numbers in the pattern
are 283, 233, 183. We realized that the rule of the
pattern was to subtract 50 each time. And we used this to find the three
missing numbers.
