Video Transcript
Adding multiples of 10 is easy with a number line. 46 plus 30 equals what.
We need to find the sum of 46 and 30 using the number line. If we start at 46 on the number line, we can add 30 by making three jumps of 10. What is 46 add 10? What number is 10 more than 46? We can add four to 46 to get to 50. And we know that four and six makes 10. So if we’ve added four, all we need to do now is add the remaining six. 50 add six takes us to 56. We need to add 10 to 56. If we can forward four, that takes us to 60 and then the remaining six. That will take us to 66.
46 and 10 more is 56. 56 and 10 more is 66. So 66 plus 10 must be 76. Did you notice what happened to the tens digit each time? Five, six, seven. The tens digit increased by one each time. This is because we’re adding one 10. Adding multiples of 10 is easy with a number line. 46, 56, 66, 76. 46 plus 30 equals 76. We started at 46 on the number line and added three lots of 10. 46 plus 30 is 76.
