### Video Transcript

Which is the missing piece from the 100 square? 57, 77, or 75.

We’re looking for this missing number. And we’re only given a piece of the 100 square. There are actually four ways we could find this missing number. Because the number is to the right of 76, we know it’s one more than 76, which is 77. Our missing number is to the left of 78, which means it’s one less than 78, which is 77. Our missing number is also below number 67 on the 100 square. As we count down a column on a 100 square, the numbers increase by 10 each time. 77 is 10 more than 67. 77 is also above 87 on the 100 square. As we count up the column on a 100 square, the numbers decrease by 10 each time. So 77 is 10 less than 87. So the missing piece from the 100 square is number 77. 77 is one more than 76 and one less than 78. It’s 10 more than 67 and 10 less than 87. The missing piece is number 77.