What's "Last digit shortcut"?

[joogle]

Manhattan's math book has the concept of "last digit shortcut". I read through an example, but honestly I'm blind as to what it's trying to achieve. Here is the actual question:

Find the unit digit of (2⁵) (3³) (4²)

The answer given is 84. What am I to do with 84?

What am I missing?

[seahawk]

Unit's digit is 84???

[bretania]

Unit's digit is a single digit. that must be a typo.
in that particular prob, the unit's digit is 4.

[Jus-do-it]

hi joogle,

this is what it means -
when u are multiplying a whole lot of numbers and u want to find the unit's digit then it is sufficient to multiply only the last digits of each of these numbers.
in your example -
2^5 -> last digit is 2
3^3 -> last digit is 7
4^2 -> last digit is 6

so to find the last digit of this multiplication u have to multiply 2*7*6
=84 who's last digit is 4

hence the answer