The principal bought 28 rolls of raffle tickets for the school carnival. One roll contained 81 tickets. About total tickets in all did the principal purchase? Choose the best estimate.

The correct answer is: 2,400

Here we need to find the expression of total 28 rolls and each have 81 tickets.
Firstly , Each rolls having 81 tickets.
1 roll = 81 tickets
For total 28 roll just multiply both side by 78
1 x 28 rolls= 81 x 28 tickets
28 rolls = 81 x 28 tickets
So the actual expression is 81 x 28, now to find the best estimate for total tickets, we need to find estimation.
Now,
81→80 , here 81 rounded down to 80.
And,
28→30, here 28 is rounded up to 30.
Therefore , the best estimate is for the total ticket is
80 x 30 = 2400 tickets
the correct answer is 2400 ( option (a)).

For finding best estimation like ,find the estimation of the expression whether is product ,addition ,subtraction or division. Round up the expressions values and then replace them in actual expression and the result expression is the answer. Apply same method in similar questions.