144 ends in an even number, so we know we can divide it by 2.
144 = 2 × 72
Let's keep going. 72 can be divided by 2 again.
144 = 2 × 2 × 36
And again...
144 = 2 × 2 × 2 × 18
And again!
144 = 2 × 2 × 2 × 2 × 9
And 9 equals 3 times 3.
144 = 2 × 2 × 2 × 2 × 3 × 3
Since we have a bunch of numbers multiplying into themselves, we should use exponents to write this.

(The little number above, called an exponent, tells you how many times to multiply the number by itself.)