1 Dot: Can you make 7 using 14 and 7 or 3 and 9? How?
2 Dots: Can you make 3 using 4/11/10 or 3/7/12? How?
3 Dots: Can you make 24 using 13/3/16 or 1/14/11? How?
1 Dot: How can you make 24 using 7, 2, 2, and 1?
2 Dots: How can you make 24 using 8, 8, 9, and 3?
3 Dots: How can you make 24 using 15, 15, 6, and 9?
September flew by but we were able to get a lot of math practice in the math lab!
In October we will continue to work on problem solving and writing constructive responses and by the end of the month fourth and fifth graders will be working on multistep problems.
During conference week, 3rd, 4th, and 5th graders will participate in their first official 24 tournament. I am posting weekly 24 challenges to help them get ready for the competition and they are able to play in the lab when the finish their work early. You can click on the "24 challenge" category to see past challenges and suggested apps for practicing 24.
Here is what our focus will be at each grade level for Mental Math Strategies:
Kindergarten: Subitizing and Ten Frames
First Grade: One/Ten More and One/Ten Less on a hundreds chart
Second Grade: Double Facts for Addition
Third Grade: Using Double Facts for Subtraction
Fourth Grade: Doubling (X2), Double, Double (X4), and Double, Double, Double (X8)
Fourth grade will also work on subtracting across zeros using manipulatives
Fifth Grade: Halving (/2), Half, Half Again (/4), and Half, Half Again, Half Again (/8)
Can you make 5 using 11 and 5 or 12 and 7? How?
Can you make 6 using 9, 3, and 12 or 1, 8, and 2? How?
Can you make 24 using 13, 3, and 16 or 1, 14, and 11? How?
1 Dot: How can you make 24 using 1, 1, 4, and 7?
2 Dots: How can you make 24 using 7, 4, 8, and 4?
3 Dots: How can you make 24 using 5, 3, 7, and 5?
1) The last Friday of a particular month is on the 25th day of the month. What day of the week is the first day of the month?
2) Three water pipes are used to fill a swimming pool. The first pipe alone takes 8 hours to fill the pool, the second pipe alone takes 12 hours to fill the pool, and the third pipe alone takes 24 hours to fill the pool. If all three pipes are opened at the same time, how long will it take to fill the pool?
3) Suppose two days ago was Sunday. What day of the week will 365 days from today then be?
1) Three weeks or 21 days before Friday the 25th is Friday the 4th. Count back to the first day. The first day of the month is Tuesday.
2) In one hour, the first pipe will fill 1/8 of the pool, the second pipe 1/12, and the third pipe 1/24. Together, in one hour, they will fill 1/8 + 1/12 + 1/24 or 3/24 + 2/24 + 1/24 = 6/24 = 1/4 of the pool. Therefore, the three pipes will fill the entire pool in 4 hours.
3) Today is Tuesday. 365 days from now is equivalent to 52 weeks and 1 day. 52 weeks from today is also Tuesday. The 365th day is Wednesday.