Shopping for Winter (Solve word problems involving estimation of sums.)

The video tutorial teaches how to use estimation to determine if you have enough money for purchases. Tiffany, with $100, needs to buy winter clothes and considers adding a scarf to her list. She uses rounding to the nearest ten to estimate costs and mentally calculates the total. Initially, her estimated total is $70, leaving room for the scarf, which she estimates at $20. With a total of $90, she confirms she can afford everything. The lesson demonstrates solving word problems using estimation of sums.

Why does Tiffany decide to round the prices to the nearest ten?

After estimating, does Tiffany have enough money to buy the scarf? Explain your reasoning.