Question

find and write the missing number to make the equations true.

1. $4 + 8 = 19 - \underline{}$
2. $\underline{} + 7 = 12 + 2$
3. $15 + \underline{} = 10 + 8$
4. $\underline{} - 6 = 9 + 5$
5. $8 + 5 = \underline{} - 3$

Explanation:

Step1: Solve equation 6

Calculate left side: $4+8=12$
Set up: $12=19-x$ → $x=19-12=7$

Step2: Solve equation 7

Calculate right side: $12+2=14$
Set up: $x+7=14$ → $x=14-7=7$

Step3: Solve equation 8

Calculate right side: $10+8=18$
Set up: $15+x=18$ → $x=18-15=3$

Step4: Solve equation 9

Calculate right side: $9+5=14$
Set up: $x-6=14$ → $x=14+6=20$

Step5: Solve equation 10

Calculate left side: $8+5=13$
Set up: $13=x-3$ → $x=13+3=16$

Answer:

1. $7$
2. $7$
3. $3$
4. $20$
5. $16$