Shop this block ... sharpener for $90 off on Amazon Canada right now. (Photo via Amazon) Having a dull set of knives is annoying — and it can also be dangerous and lead to accidents in the kitchen.

"Love that it comes with a sharper!" writes one person, with another saying the tool "did a great job of sharpening" an old, dull knife. Others say that it's "definitely a worthwhile investment" and ...