Add it up!
Find the difference!
About how much?
Decimal Detectives
Real-World Challenge
100

0.6 + 0.9

1.5

100

0.9 - 0.4

0.5

100

4.2 + 3.1

7

100

Find the missing number: 0.7 + __ = 1.

0.3

100

Mia walks 1.4 miles before lunch and 2.3 miles afterward. How far does she walk altogether?

3.7 miles

200

2.47 + 3.36

5.83

200

5.86 - 2.43

3.43

200

Estimate: 8.76 + 6.58

16

200

Find the missing number: ___ + 2.65 = 6.9

4.25

200

A ribbon is 8.5 meters long. Noah cuts off 3.76 meters. How much ribbon remains?

4.74 meters

300

8.7 + 6.85

15.55

300

7.3 - 2.68

4.68

300

Estimate: 23.81 - 9.36

15

300

12.4 - __ = 7.86

4.54

300

lena buys a notebook for $4.85 and markers for $7.68. She pays with $20. How much change should she receive?  

$7.47

400

27.688

15.7921

400

30.04 - 16.87

13.17

400

A backpack costs $38.79, a lunch bag costs $16.24, and a water bottle costs $12.68. Estimate the total.

$68

400

Leo says 6.4 + 2.38 = 3.02. What mistake did he probably make, and what is the correct sum?

He likely lined up the last digits instead of the decimal points, treating 6.4 as 0.64. Correct sum: 8.78.

400

One package weighs 6.35 pounds. A second package weighs 1.78 pounds less than the first. What is their combined weight?

10.92 pounds

500

18.75 + 6.8 + 24.46

50.01

500

100 - 47.68 - 18.75

35.57

500

You have $75. You buy a game for $28.65 and a controller for $19.49. Estimate how much money remains.

$27

500

Two numbers have a sum of 10. Their difference is 2.6. What are the numbers?

6.3 and 3.7

500

A class needs $125 for a field trip. It collects $38.75 on Monday and $46.80 on Tuesday, then spends $12.65 on fundraising supplies. How much more money does the class need?

$52.10