# Question Video: Subtracting One-Digit Numbers from Three-Digit Numbers to Solve Word Problems

Elizabeth buys a notebook that has 109 pages. She completes her assignments in 7 pages. How many blank pages are left in the notebook?

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### Video Transcript

Elizabeth buys a notebook that has 109 pages. She completes her assignments in seven pages. How many blank pages are left in the notebook?

This is a subtraction problem. Elizabeth has 109 pages in her notebook to begin with. And she uses seven pages to complete her assignments. To find out how many pages she has left in her notebook, we need to subtract seven from 109.

Did you notice that we’re subtracting a one-digit number from a three-digit number? We can start by first subtracting the ones. Seven only has a ones digit, so we just need to subtract seven ones from our nine ones. We need to start at the number 109 and count back in ones seven times. One, two, three, four, five, six, seven. 109, 108, 107, 106, 105, 104, 103, 102. If Elizabeth’s notebook has 109 pages and she uses seven pages, there will be 102 pages left in her notebook. 109 subtract seven equals 102.