500
Miss Upright bought gifts for her students for Christmas. If she gave a gift to each child every day for 5 days in a row, she would have to buy gifts in the following quantities:
16, 32, 48, 64, 80 16, 160, 1,600, 16,000
4, 8, 12, 16 16, 17, 18, 19, 20
What is 16, 32, 48, 64, 80?