Maths 2019

Name:MistyDate:20/03/2019

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Exploring addition Addition/Subtraction Strategies We are practising strategies for adding and subtracting numbers. Exercise 1: Jumping the number line example 27 + … = 71 We can use the jumping the number line strategy to solve this 3 27 30 70 71 … = 3 + 40 + 1 = 44 What to do Draw a number line like the one in the example to work out the answers to each of these problems. 1) 26 +29 … = 55 (2) 38 +24 … = 62 (3) 37 + 54… = 91( 4) 105 + 126… = 231 (5) 142 + … 70= 212 (6) 351 +153 … = 504
In these next problems, the box sometimes comes first. Explain why you can still use the strategy above to work out the answer.
7) …27 + 32 = 59 (8) … 22+ 49 = 71 (9) … 345+ 108 = 453 10) 2.7 +2.5 … = 5.2 (11) 1.9 +5.2 … = 7.1 (12) 6.7 +25.4 … = 32.1 13) 3.47 + …2.78 = 6.25 (14) 11.55 +16.35 … = 27.9 (15) … 6.4+ 3.8 = 10.2 16) …32.5 + 192.6 = 225.1 (17) …789.93 + 1 370.25= 2,160.18
18) Write a problem of your own like number 15 that the jumping the number line strategy would be a sensible strategy for. 19) 26 +29 … = 55 Show how you could solve this problem using a different strategy. Exercise 2: Don’t subtract - add What to do Write these subtraction problems as addition problems, then answer them. 1) 60 - 26 =46 … (2) 70 – 38 =48 … (3) 92 - 47 =45 … 4) 405 – 347 =1054 … (5) 352 - 147 =207 … (6) 530 – 358 =192 … 7) 4,750 – 3,860 =1,080 … (8) 6,704 – 3,819 =3,095 … (9) 2.7 – 1.9 =0.8 … 10) 6.3 - 2.7 = 13.4… (11) 8.3 - 3.9 =4.4 … (12) 45.3 - 26.7 =122.4 … 13) Write a subtraction problem of your own like number 11 that the addition strategy would be a sensible strategy for.
14) 60 – 26 =34

… Show how you could solve this problem using a different strategy.