Video Transcript
Addition or Subtraction of Tens
from Two-Digit Numbers
In this video, we will learn how to
find 10 more or 10 less than a two-digit number using base ten blocks and place
value charts. What number do these base ten
blocks show? These blocks are called the tens
blocks. Each of these towers is worth one
ten. We have two tens. So we can write a number two in the
tens column on the place value chart. These bricks are the ones
blocks. Let’s count how many there are:
one, two, three, four, five, six, seven, eight. So we can write eight in the ones
column on the place value chart. Two tens and eight ones makes the
number 28. Let’s practice with some example
questions.
Find 10 more than 37.
We can use base ten blocks to
help. 37 has three tens. So we need three tens blocks:
10, 20, 30. 37 has seven ones. Three tens and seven ones makes
37. We need to find 10 more than
37. So we can add one more tens
block. Now we have four tens and seven
ones. 10 more than 37 is 47.
We want to show that 10 less
than 34 is 24. How many ten rods should we
take away to show this? 10 less than 34 is 24.
34 is three tens and four
ones. We know that 10 less than 34 is
24. How many ten rods should we
take away to show 24? We can see from the place value
chart that 24 has two tens. So we needed to take away one
ten rod to show 24.
In this video, we’ve learned how to
find 10 more or 10 less than a two-digit number using base ten blocks and place
value charts.
