Monday, 9 February 2015

Greedy 9 in Math

We have been working on the “Greedy 9” and “Greedy 99” strategy to help us add and subtract numbers. This is a great strategy to practice at home to develop fluency for mental math for both 1 and 2 digit numbers. A couple things you can do at home to help with this strategy are:

 -Practice what number is 10 less and 10 more than a given number. Ask what is 10 less than 13, 25, 89, 134, 205 etc. This is great to practice while walking or driving somewhere.

 -Practice adding and subtracting 9 or 99 using the Greedy 9 or Greedy 99 strategy. Start with subtracting 9 and then move to more challenging numbers when your child seems more confident in this strategy. Always keep it positive.

 Here are some examples, 15-9= Think: 15-10=5 +1=6 So 15-9=6

 27-9= Think: 27-10=17+1=18

 85-9= Think: 85-10=75+1=76

 34-19= Think: 34-20+1=

 144-99= Think: 144-100=44+1=45

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