But Leah's greatest understanding of this topic came from the exercises in Hands-On Math!: Ready-To-Use Games & Activities for Grades 4-8on pages 69, 71, 74. The book is good and the author always gives multiple lessons for each topic and she moves from the concrete to the abstract. I found poker chips in blue and red to be helpful for the introductory lesson. The final assignment using grocery store ads was quite effective. Leah used it for her MLB illustration.
Today she shared her draft of her MLB text with me and I was very happy with it. She wrote:
Ratio is the relationship between one amount and another amount. For example you might be in a store and see a sign that says 2 bottles of milk for four dollars. That's a ratio. How many jars of milk can you get for sixteen dollars? You could get 8 jars of milk. That is an example of how you can multiply a ratio. Another example is hummingbird food. When you make hummingbird food you use a ratio of one cup sugar to 4 cups water. Using that ratio you can make as much hummingbird food as you want.
I accidentally showed her how to write ratios like analogies (piglet:sow :: lamb:ewe) and not like ratios, which are 1:2 = 2:4. So I had to correct myself. But I was able to show her a trick I found online when googling "How are colons used in ratios?" when I had a sinking suspicion I was wrong. Leah was able to check her own work when doing the grocery store ad assignment by simply cross-multiplying.
a:b = c:d
a x d = b x c
1:2 = 2:4
1 x 4 = 2 x 2
If they don't equal one another, your ratio was not calculated correctly.
We are enjoying this unit and Leah's loving baking so much! All the girls are. Now they are doing even more baking for fun. Yesterday Natalie made cornbread at lunchtime and then surprised us all with homemade strawberry shortcakes at tea time. She even went to the garden and picked some roses for the center of the table. We are in NO sports or activities and never leave the house except to grocery shop and hit the library once a week. Yes, there are downsides to that -- in terms of enrichment and socialization -- but there are upsides too and it's a fact of life when 1) you have a little baby and 2) you share a car with your husband who has to go off to work each day. One of the upsides is things like surprise homemade strawberry shortcake... and Leah is in the kitchen right now making Cream Cheese-Filled Banana Bread.