Exercise 7

In this practice session, our main objective is to excel in addition and subtraction within the range 1 to 99.
Upon each website refresh, a set of 3 random questions will emerge. It is crucial to perform the exercises accurately, swiftly, and with mastery before proceeding to the subsequent exercise.

When adding or subtracting from the thumb of your left or Right hand, the following patterns can be observed:
  • Right hand: +4 = +5 -1, left hand: +40 = +50 -10
  • Right hand: +3 = +5 -2, left hand: +30 = +50 -20
  • Right hand: +2 = +5 -3, left hand: +20 = +50 -30
  • Right hand: +1 = +5 -4, left hand: +10 = +50 -40
  • Right hand: -4 = -5 +1, left hand: -40 = -50 +10
  • Right hand: -3 = -5 +2, left hand: -30 = -50 +20
  • Right hand: -2 = -5 +3, left hand: -20 = -50 +30
  • Right hand: -1 = -5 +4, left hand: -10 = -50 +40
In the 7th exercise:
  • +9 = +10 –1
  • +8 = +10 –2
  • +7 = +10 –3
  • +6 = +10 –4
  • +5 = +10 –5
  • +4 = +10 –6
  • +3 = +10 –7
  • +2 = +10 –8
  • +1 = +10 –9
  • -9 = -10 +1
  • -8 = -10 +2
  • -7 = -10 +3
  • -6 = -10 +4
  • -5 = -10 +5
  • -4 = -10 +6
  • -3 = -10 +7
  • -2 = -10 +8
  • -1 = -10 +9
Exercise 7.1
7 - 5 + 8 = ?
- 5 =
+ 8 = 2 + 10 - 2 =

Congratulations if your response equals 10
Exercise 7.2
12 + 10 + 12 - 2 - 14 - 9 - 8 + 13 - 10 + 14 + 4 + 10 = ?
+ 10 =
+ 12 =
- 2 =
- 14 =
- 9 = 18 - 10 + 1 =
- 8 =
+ 13 =
- 10 =
+ 14 =
+ 4 = 18 + 10 - 6 =
+ 10 =

Congratulations if your response equals 32
Exercise 7.3
8 + 7 + 6 - 16 + 13 + 7 + 6 + 3 + 9 - 14 + 9 + 14 + 10 + 6 - 2 + 5 - 5 + 8 = ?
+ 7 = 8 + 10 - 3 =
+ 6 = 15 + 10 - 4 =
- 16 =
+ 13 =
+ 7 = 18 + 10 - 3 =
+ 6 = 25 + 10 - 4 =
+ 3 =
+ 9 = 34 + 10 - 1 =
- 14 =
+ 9 = 29 + 10 - 1 =
+ 14 =
+ 10 =
+ 6 =
- 2 =
+ 5 = 66 + 10 - 5 =
- 5 = 71 - 10 + 5 =
+ 8 = 66 + 10 - 2 =

Congratulations if your response equals 74
Upon each website refresh, a set of 3 random questions will emerge. It is crucial to perform the exercises accurately, swiftly, and with mastery before proceeding to the subsequent exercise.

When adding or subtracting from the thumb of your left or Right hand, the following patterns can be observed:
  • Right hand: +4 = +5 -1, left hand: +40 = +50 -10
  • Right hand: +3 = +5 -2, left hand: +30 = +50 -20
  • Right hand: +2 = +5 -3, left hand: +20 = +50 -30
  • Right hand: +1 = +5 -4, left hand: +10 = +50 -40
  • Right hand: -4 = -5 +1, left hand: -40 = -50 +10
  • Right hand: -3 = -5 +2, left hand: -30 = -50 +20
  • Right hand: -2 = -5 +3, left hand: -20 = -50 +30
  • Right hand: -1 = -5 +4, left hand: -10 = -50 +40

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