Answers

2016-01-15T23:07:05+05:30
1+9 coz most children mistake it as too many numbers to add
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1+9 is more difficult because u have to add 9 digits after 1 which can be confusing and hard more then 9+1 coz where u only have to add 1 digit after nine so i think that 1+9 is more difficult then 9+1
2016-01-15T23:13:47+05:30
1+9 is more difficult to teach 

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