Thursday, October 08, 2009

Cube City

There is a difference between mindlessly checking things off a to-do list and doing things worth doing. Pamela frequently confirms the meaning of what we are doing. Recently, she started watching DVDs without closed captioning and sets the audio to either French or Spanish! She pulled out an old twaddly companion book to a kid's tape for learning Spanish words, and she reviews it for fun. Second, Pamela has started building things, mainly houses, with the Math-U-See blocks. Unlike her brother, who will never admit to how recently he put away his Legos, she has succumbed to the Lego bug. I may just drag David's collection downstairs for her! She still plans to trick or treat this year, dressed as a mom, taking her babies (Baby Alive and Baby David) out because they are toddlers now. When she flips through old photographs and asks me a question, she turns it so that I can see without hinting, "I can't see it." When we do money transactions, Pamela asks what we are doing so she can figure out if it is negative or positive. Making mathematical connections to the real world because she can easily memorize without understanding.

To teach volume, I cut out a bunch of flattened cubes (a spreadsheet I made in Excel), built them, and taped them together. We recycled some of the boxes used for calculating surface area and filled them with cubes. Not only did it give her a feel for what volume is (how much space an object takes up), building with cubes spotlights the idea of cubic units being very different from square units. We carefully took the cubes out of the box and compared it to it, side by side. We separated each layer of the volume to enable Pamela to be certain of her count.
Pamela did free lance explorations in which I gave her 20 cubes and let her figure out how many ways to create a volume of 20 cubic inches. Another variation was to take a pile of blocks, create a rectangular prism, and count the dimensions and volume. Activities like this appealed to her orderly, patterned mind. She recorded everything she did in charts to allow her to discover the formula for volume.

By the fourth example of volume, Pamela spotted the formula for volume: length times width times depth. She quickly transition from doing hands-on work to picture (even trying her hand at drawing a 3-D box) to words and symbols. Once she solidified her ability to do volume problems, I introduced one variation: being given a problem with mixed units (1 foot by 10 inches by 14 inches). She is learning to be vigilant about checking the units before labeling her drawings.

Covering a Surface
Pamela struggled with coverage problems like,
Susan needs to buy paint to cover 2100 square feet. One gallon of paint covers 400 square feet. How many gallons of paint does she need?

I realized she did not quite understand what the problem was asking so we backed up and did some concrete activities like covering a 9" x 12" notebook with 3" x 3" sticky notes (pictured left) or covering books with index cards (or cut-up index cards of a standard size to make the numbers work). When we made the leap to word problems, I knew Pamela understood when she illustrated her problem with paint cans.

The next variation I plan to address are house problems including painting or covering sides with siding (you only hit the sides, unless you have triangular shaped attics) and shingling roofs. More variations will involve subtracting out the area of doors and windows or applying two coats of paint.


Happy Elf Mom (Christine) said...

I love it! We use standard counting rods and wooden baby blocks, but the little boxes are just so cute!

walking said...

Yes, well, pastel cardstock really does complete the look . . .

walking said...

Plus I'm too cheap to shell out the big bucks for expensive plastic manipulatives . . . AND they are biodegradable, too! Something for everyone!

Happy Elf Mom (Christine) said...

Thrift store find for us LOL. No way I could spend that kind of money on a plastic cube, either. I've priced 'em and they're incredibly expensive.

Penny said...


We did addition and subtraction with french fries today while we were eating lunch. Need some cubes! lol

walking said...

The price is right too! Cutting them up and taping them made me a bit buggy!