Estimating Sums & Differences: Fun 3-Digit Challenges

A bakery made 245 cookies in the morning and 378 cookies in the afternoon. How many cookies did they make in total? Estimate the sum first.

• 500

• 700

• 623

• 600

There are 512 apples in a basket. If 178 apples are taken out, how many apples are left? Use a number line to help you calculate.

• 512

• 178

• 334

• 3340

A library has 345 books. If they buy 256 more books, how many books will they have altogether? Estimate the total first.

• 700

• 601

• 500

• 600

A toy store had 678 toys. They sold 289 toys. How many toys are left in the store? Use a number line to find the answer.

• 350

• 389

• 400

• 450

A farmer harvested 423 carrots and then harvested 189 more. How many carrots did he harvest in total? Estimate the sum before calculating.

• 500

• 600

• 700

• 612

In a classroom, there are 256 pencils. If 134 pencils are given to students, how many pencils remain? Use a number line to solve this problem.

• 122

• 200

• 150

• 130

A zoo has 512 visitors in the morning and 289 visitors in the afternoon. How many visitors did the zoo have that day? Estimate the total first.

• 700

• 801

• 600

• 900

A school has 450 students. If 175 students go on a field trip, how many students are left at school? Use a number line to find the answer.

• 275

• 400

• 300

• 250

A pet store has 367 fish. If they sell 128 fish, how many fish do they have left? Estimate the difference first.

• 300

• 200

• 239

• 245

A candy shop made 234 candies on Monday and 456 candies on Tuesday. How many candies did they make in total? Use a number line to help you calculate.

• 600

• 700

• 690

• 500