What number is one less than 10 plus five?
First, we need to add 10 and five. And then we need to find the number which is one less. We have one tens rod, which is worth 10 or one ten. And we have five ones. One ten and five ones makes 15. One less than 15 is 14. We had five ones. We took away one. We’re left with four. One 10 and four ones is 14. The number which is one less than 10 plus five is 14. 10 plus five is 15, and one less than 15 is 14.