A book has 276 pages. Amina has read a third of the book. How many pages are left for Amina to read?
First, we need to calculate how many pages Amina has already read, or one-third of 276. To find a third, we need to divide 276 by three. Two is less than three. So we can move a digit to the right and calculate 27 divided by three. Or, how many threes are there in 27? Nine times three is 27. Now, we need to divide six by three. Two threes make six. So Amina has read 92 pages. We know the book has 276 pages. So we need to subtract 92 from 276 to tell us how many pages Amina has left to read.
A quick way to calculate this would be to take away 100 from 276 because 92 is only eight less than 100. Then we can adjust our answer by adding eight because we took away eight too many. 176 plus eight is 184. So Amina has 184 pages left to read.
First, we calculated a third of 276 because Amina had already read a third of the book. To do this, we divided 276 by three, which is 92. Then we subtracted 92 from 276, which is the total number of pages in the book, which gave us our answer, 184 pages.