Let's solve each equation step by step to
find the value of the variable. We'll use basic algebra: isolate the variable on one side of the equation by performing inverse operations.
---
a) 7 - n = 3
To find `n`, subtract 3 from 7:
$$
7 - 3 = n \Rightarrow n = 4
$$
✔ n = 4
---
b) p + 5 = 19
Subtract 5 from both sides:
$$
p = 19 - 5 = 14
$$
✔ p = 14
---
c) 22 + n = 33
Subtract 22 from both sides:
$$
n = 33 - 22 = 11
$$
✔ n = 11
---
d) 8 - 4 = p
Just compute:
$$
p = 4
$$
✔ p = 4
---
e) 4 + y = 15
Subtract 4:
$$
y = 15 - 4 = 11
$$
✔ y = 11
---
f) n - 7 = 20
Add 7 to both sides:
$$
n = 20 + 7 = 27
$$
✔ n = 27
---
g) 61 + n = 67
Subtract 61:
$$
n = 67 - 61 = 6
$$
✔ n = 6
---
h) 135 - a = 125
Subtract 125 from 135:
$$
135 - 125 = a \Rightarrow a = 10
$$
✔ a = 10
---
i) 13 + 13 = p
Add:
$$
p = 26
$$
✔ p = 26
---
j) a - 11 = 8
Add 11:
$$
a = 8 + 11 = 19
$$
✔ a = 19
---
k) 21 + 43 = n
Add:
$$
n = 64
$$
✔ n = 64
---
l) 35 - x = 27
Subtract 27 from 35:
$$
x = 35 - 27 = 8
$$
✔ x = 8
---
m) 4 + 8 = n
Add:
$$
n = 12
$$
✔ n = 12
---
n) a + 21 = 47
Subtract 21:
$$
a = 47 - 21 = 26
$$
✔ a = 26
---
o) 18 + 13 = n
Add:
$$
n = 31
$$
✔ n = 31
---
p) 43 + n = 49
Subtract 43:
$$
n = 49 - 43 = 6
$$
✔ n = 6
---
q) 40 - y = 28
Subtract 28 from 40:
$$
y = 40 - 28 = 12
$$
✔ y = 12
---
r) x + 76 = 84
Subtract 76:
$$
x = 84 - 76 = 8
$$
✔ x = 8
---
s) 80 + n = 88
Subtract 80:
$$
n = 88 - 80 = 8
$$
✔ n = 8
---
t) x + 62 = 70
Subtract 62:
$$
x = 70 - 62 = 8
$$
✔ x = 8
---
u) 17 + n = 34
Subtract 17:
$$
n = 34 - 17 = 17
$$
✔ n = 17
---
v) 7 + n = 21
Subtract 7:
$$
n = 21 - 7 = 14
$$
✔ n = 14
---
w) 16 + 12 = n
Add:
$$
n = 28
$$
✔ n = 28
---
##
✔ Final Answers:
| Letter | Value |
|--------|-------|
| a) n | 4 |
| b) p | 14 |
| c) n | 11 |
| d) p | 4 |
| e) y | 11 |
| f) n | 27 |
| g) n | 6 |
| h) a | 10 |
| i) p | 26 |
| j) a | 19 |
| k) n | 64 |
| l) x | 8 |
| m) n | 12 |
| n) a | 26 |
| o) n | 31 |
| p) n | 6 |
| q) y | 12 |
| r) x | 8 |
| s) n | 8 |
| t) x | 8 |
| u) n | 17 |
| v) n | 14 |
| w) n | 28 |
---
🔍 Summary Tips:
- If the variable is being
added, subtract the number from both sides.
- If the variable is being
subtracted, add the number to both sides.
- Always isolate the variable (get it alone on one side).
Let me know if you'd like this in a printable format or with explanations for each!
Parent Tip: Review the logic above to help your child master the concept of missing variable worksheet for third graders.
