Video Transcript
What is 10 more than 1,212? What is 10 less than 1,212?
This question is all about how
numbers change when we find 10 more or 10 less than them. And it’s the same number we’re
starting from each time: 1,212. Now because we’re counting in tens
here, finding 10 more or 10 less, we can use our knowledge of place value to help us
because one of the digits in a four-digit number is worth tens. 1,212 contains one 1,000, two 100s,
one 10, and two ones. In the first part of our question,
we’re asked to find 10 more than this number. Well, as we’ve just said, 1,212
contains one 10. And if we find 10 more than this
number, we need to add one more 10. We’ve added another 10s block, and
now we have two 10s. None of the other digits have
changed. We still have one 1,000, two 100s,
and two ones. But instead of one group of 10, we
now have two. 10 more than 1,212 is 1,222.
Now let’s use the same idea, but
this time we’re going to find 10 less than our number. So, just like before, we can start
with 1,212. And which part of our number do you
think is going to change if we need to find 10 less than this? Well with a question like this, we
always need to start by looking at the tens digit. Our number contains one 10. So if we find 10 less than this,
we’re going to need to take away this 10. Instead of one 10, we now have zero
tens. Once again, the thousands digit,
the hundreds digit, and the ones digit in our answer are exactly the same. They haven’t changed at all. However, because we have 10 less
instead of one 10, we need to write a zero in the tens place.
We’ve used our knowledge of place
value to find 10 more and 10 less than the same number. 10 more than 1,212 is 1,222, and 10
Less than 1,212 is 1,202.
