Problem 5-3A Perpetual: Alternative cost flows LO P1

Montoure Company uses a perpetual inventory system. It entered into the following calendar-year purchases and sales transactions

Date

Activities

Units Acquired at Cost

Units Sold at Retail

Jan.

1

Beginning inventory

570

units

@ $50 per unit

Feb.

10

Purchase

380

units

@ $47 per unit

Mar.

13

Purchase

190

units

@ $35 per unit

Mar.

15

Sales

700

units

@ $75 per unit

Aug.

21

Purchase

200

units

@ $55 per unit

Sept.

5

Purchase

590

units

@ $53 per unit

Sept.

10

Sales

790

units

@ $75 per unit

Totals

1,930

units

1,490

units

2. Compute the number of units in ending inventory.

the answer is 440

but can you please explain how you get 440 as the answer??