Describe two different ways that you could find the product 4 × 998 using mental math. Find the product and complete the explanation of why your model works. (1) Think of 998 as 1,000 − 2. So, 4 ×
= 4(1,000 − 2). By the
(select)
Property, 4(1,000 − 2) = 4,000 − 8 =
.

(2) Think of 998 as 900 + 90 +
. By the
(select)
Property, 4(900 + 90 + 8) = 3,600 + 360 +
=
.