To obtain an equivalent fraction by multiplying, multiply the whole fraction by any single number. Example: 3/4 multiplied by 3 is 9/12. Those fractions are equivalent.
To obtain an equivalent fraction by dividing, look at the top number and the bottom number. If they both can be divided by a number without it being a decimal, it’s an equivalent fraction. Example: 8/10, both of those numbers can be divided by 2 that isn’t a decimal, 4/5. 4/5 and 8/10 are equivalent