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.