Both backward and backwards are correct, but most sources say that when you're using the word as an adverb, backward is standard in American English and backwards is standard in British English.
How do you use backward in a sentence?
in or to or toward a past time.
- Youth looks forward and age backward.
- He who does not advance falls backward.
- Without a backward glance, he walked away.
- Hannah took a step backward.
- For life goes not backward nor tarries with yesterday.
- This part of the country is still backward.
Is it forward or backward?
The preferred form is without the -s in American English, with it in British English. The same is true for other directional words, such as upward, downward, forward, and backward, as well as afterward. The use of afterwards and backwards as adverbs is neither rare nor incorrect.