If you have 1000 pencils and you divide by 7 teachers, you would have 142 pencils divided evenly. Then you would take the 142 pencils and multiply by 7 which will give you a total of 994 pencils that went to the teachers in total. So the remaining pencils would be 1000 minus 994 and the total left over will be 6 pencils. I hope this helps.