Sept 2018 (CML)

I will post seven new problems every weekend, one for each day of the week. The idea is that you work on your own during the week and I will post answers the following Saturday.  For those of you who practiced with me last year, the process is similar.

For instructions on submitting weekly answers, click on the “Logistics” tab.
For previously posted problems, click on the “Archive” tab.
For previous prizes, click on the “News” tab.


 

Week of Sept 23 – Sept 29: All about fractions.

Click GoogleForm to submit answers by Sat, Sept 29.

Sept 23: What is the reciprocal of {1\over 2} +{1\over 4}?

Answer: 4\over 3

Sept 24: How much bigger is {2018\over 25} + 25 than {{2018+25}\over 25}?

Answer: 24

Sept 25: What number must we add to 3\over 10 to get 7\over 15?

Answer: 1\over 6

Sept 26: What number must we subtract 5\over 9 from to get 1\over 6?

Answer: 7\over 18

Sept 27: What number must we subtract from 5\over 6 to get 1\over 10?

Answer: 11\over 15

Sept 28: Simplify {2\over 3}\times {4\over 5}+{2\over 3}\times {11\over 10}.

Answer: 19\over 15

Sept 29: Which one is bigger 99 or 99 \div {101\over 102}?

Answer: 99 \div {101\over 102}

 


Week of Sept 16 – Sept 22: Can you do the following calculations in your head?

Click GoogleForm to submit answers by Sat, Sept 29.

Sept 16: Compute the product 25 \cdot (6\cdot 12) .

Answer: 1800

Sept 17: Simplify the expression ((1 \cdot 2) + (3\cdot 4) - (5\cdot 6) + (7\cdot 8)) \cdot (9\cdot 0)

Answer: 0

Sept 18: What is the value (184 + 267 + 398) – (84 + 67 + 98)?

Answer: 600

Sept 19: What is the value 1 -3 + 5 – 7 + 9 – 11 + 13 – 15 + 17 – 19?

Answer: -10

Sept 20: What is the value 693 \cdot 1587 - 692 \cdot 1587?

Answer: 1587

Sept 21: What is the value 4\cdot 199 + 5\cdot 199 + 198?

Answer: 1990-1 = 1989

Sept 22: What is the value 91 + 92 + … + 98 + 99?

Answer: 855

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