2. estimating differences

ESTIMATING DIFFERENCES

4 753

84 387

59 367 38 732

3 575 4 385

547 203

47 259

1 543

Hundreds Thousands

1) 253 2) 3 4373) 125 4) 6 0535) 478 6) 4 8577) 659 8) 8 2109) 304 10) 7 489

Mr. Cruz has 782 square meters of land planted with corn and

575 square meters planted with palay. About how many

square meters more of land were planted with palay than with

corn?

What is asked in the problem?What operation are we going to use?

What will be the number sentence for the problem?

Execute our planAround 200 square meters of land were planted to palay than corn

782 800 -575 -600

Check your work

Exact Difference Estimated Difference

782 800 - 575_ - 600

207 200207 I close to 200

Guided Practice

4 615 - 3 243

536 - 275

8 937 - 4 352

6 836 - 2 595

483 - 124

882 - 416

6 247 - 3 281

7 086 -2 540

748 -334

296 - 154

Remember:

To estimate the difference:

a. Round the minuend and the subtrahend to their greatest place value.

b. Subtract the rounded numbers.

Complete the puzzle boxes by estimating. The answer in the bottom right corner of each box will be the same when subtracting across or down.

1 287 891888 641

Estimate the difference by rounding the numbers to its highest place value then subtract. Write the answer in your notebook.1) 643 2) 846 -448 - 551

3) 558 4) 452 - 99 -125

5) 758 -174

6) 8 435 7) 9 071 - 2 526 - 2 052

8) 4 892 9) 8 465 - 1 261 - 3 259

10) 4 936 - 2 143

Assignment:

Write a good estimate after each problem, then solve.

1. Mr. Reyes wanted to sell 302 tickets for a cultural show. He sold 191 tickets. About how many more tickets should he sell?

Estimate by rounding to the nearest hundredsAnswer:

2. There are 8 936 books in Manuel L. Quezon Elementary School. Manuel Roxas Elementary School has 7 642 books in its library. How many more books does Manuel L. Quezon Elementary School have than Manuel Roxas Elementary School?

Estimate by rounding to the nearest thousands:Answer: