Practice with the help of Spectrum Math Grade 1 Answer Key Chapter 3 Lesson 3.13 Using Addition for Subtraction regularly and improve your accuracy in solving questions.

Think addition for subtraction. Solve each problem. When three is subtracted from seventeen it gives the value 14 as shown below.
i.e.  17 -3 = 14 Let the unknown number be x
3 + x = 17
x = 17 – 3
x = 14
Therefore 3 +14 is equal to 17. When five are subtracted from twenty it gives the value 15 as shown below.
i.e.  20 – 5 = 15 Let the unknown number be x
5 + x = 20
x = 20 – 5
x = 15
Therefore 5 +15 is equal to 20 . When 5 are subtracted from Nineteen it gives the value 14 as shown below.
i.e.  19 – 5 = 14 Let the unknown number be x
5 + x = 19
x = 19 – 5
x = 14
Therefore 5 +14 is equal to 19 . When 1 is subtracted from Eighteen it gives the value 17 as shown below.
i.e.  18 – 1 = 17  Let the unknown number be x
1 + x = 18
x = 18 – 1
x = 17
Therefore 1 +17 is equal to 18 . When 4 are subtracted from Four it gives the value 11 as shown below.
i.e.  15 – 4 = 11 Let the unknown number be x
4 + x = 15
x = 15 – 4
x = 11
Therefore 4 +11 is equal to 15. When 2 are subtracted from Fourteen it gives the value 12 as shown below.
i.e.  14 – 2 = 12 Let the unknown number be x
2 + x = 14
x = 14 – 2
x = 12
Therefore 2 +x is equal to 14. When 1 is subtracted from Sixteen it gives the value 15 as shown below.
i.e.  16 – 1 = 15 Let the unknown number be x
1 + x = 16
x = 16 – 1
x = 15
Therefore 1 + 15 is equal to 16. When 6 are subtracted from Twenty it gives the value 14 as shown below.
i.e. 20  –  6 = 14 Let the unknown number be x
6 + x = 20
x = 20 – 6
x = 14
Therefore 6 + 14 is equal to 20. When 0 is subtracted from Thirteen it gives the value 13 as shown below. 