Åk 6–9
  • Start
  • 1. Welcome to Operators and Calculation Rules
  • 2. Addition and Subtraction
  • 3. Multiplication And Division
  • 4. Factorization
  • 5. Setting Up Calculations
  • 6. Powers
  • 7. Square Roots
  • 8. Mathematical Rules
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    English/Русский
    2.7 Exercises – Addition and subtraction

    1. Do the calculations according to the example below.

    Ex: 11 + 22 (10+20) + (1+2) = 33
    a) 24 + 51
    b) 76 - 24
    c) 32 + 47
    d) 94 - 61
    e) 574 + 203
    f) 2,371 + 3,428
    g) 9,687 - 4,585
    		 

    2. First make tens and calculate like the example below.

    Ex: 8 + 9 + 5 = 20 + 2 = 22
    a) 4 + 7 + 6 + 2 =
    b) 3 + 4 + 1 + 7 =
    c) 25 + 4 + 5 + 6 =
    d) 18 + 5 + 32 + 2 =
    e) 42 + 5 + 28 + 23 =
    f) 9 + 3 + 34 + 46 =
    g) 24 + 36 + 12 + 3 =
    		 
    3. Do the calculations by using approximation. 
    Ex: 46 + 32 ≈ 50 + 30 = 80
    a) 23 + 19 ≈
    b) 67 - 34 ≈
    c) 54 - 22 ≈
    d) 69 + 28 ≈
    e) 53 + 66 ≈
    f) 72 + 56 ≈
    g) 93 - 27 ≈
    		 

    4. Round off first to the hundreds and then calculate by using approximation.

    Ex: 290 + 118 ≈ 300 + 100 = 400
    a) 753 + 275 ≈
    b) 486 - 91 ≈
    c) 867 + 151 ≈
    d) 174 + 748 ≈
    e) 425 - 127 ≈
    f) 819 - 311 ≈
    g) 367 + 474 ≈