Let’s solve each problem one by one. We’ll be careful with the signs (positive and negative) and decimal places.
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1) 5.08 - 30
Think: You’re taking away more than you have → answer will be negative.
30 - 5.08 = 24.92 → so 5.08 - 30 =
-24.92
2) 24 + 71.08
Just add them: 24 + 71.08 =
95.08
3) 87 - (-47)
Subtracting a negative is like adding: 87 + 47 =
134
4) 85 - (-28.005)
Again, subtracting negative = adding: 85 + 28.005 =
113.005
5) 62.51 + (-97.08)
Adding a negative = subtracting: 62.51 - 97.08
97.08 - 62.51 = 34.57 → since we’re subtracting bigger from smaller, it’s
-34.57
6) 78.001 + (-60)
= 78.001 - 60 =
18.001
7) 81.1 - 45
Simple subtraction: 81.1 - 45 =
36.1
8) 8.3 + (-56.646)
= 8.3 - 56.646
56.646 - 8.3 = 48.346 → so answer is
-48.346
9) 7.095 + (-84)
= 7.095 - 84
84 - 7.095 = 76.905 → so
-76.905
10) 44.07 + (-33.1)
= 44.07 - 33.1 =
10.97
11) 98.1 + 56.059
Add decimals carefully:
98.100
+56.059
=
154.159
12) 50.62 + 63.008
50.620
+63.008
=
113.628
13) 33.82 + 40
=
73.82
14) 77.04 - 98.3
Bigger number being subtracted → negative result
98.3 - 77.04 = 21.26 → so
-21.26
15) 10 + (-77)
= 10 - 77 =
-67
16) 33 - (-49)
= 33 + 49 =
82
17) 83 + (-66)
= 83 - 66 =
17
18) 18.09 - (-21.914)
= 18.09 + 21.914 =
40.004
19) 51 - 76
76 - 51 = 25 → so
-25
20) 79 - 17.9
79.0 - 17.9 =
61.1
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Final Answer:
1. -24.92
2. 95.08
3. 134
4. 113.005
5. -34.57
6. 18.001
7. 36.1
8. -48.346
9. -76.905
10. 10.97
11. 154.159
12. 113.628
13. 73.82
14. -21.26
15. -67
16. 82
17. 17
18. 40.004
19. -25
20. 61.1
Parent Tip: Review the logic above to help your child master the concept of adding and subtracting rational numbers.
