When my son was a baby, I used life integration to weave learning into every day activities. I let him choose what we did and simply infused those activities with learning. Here's an example of how you can use life integration to teach your little ones all kinds of things without ever using a flash card or forcing them to sit through anything they don't want to do.
Pick a letter for the day and look for opportunities all day long to explore things that start with that letter. Maybe while you're eating breakfast, you notice a rabbit in your yard.
"Look! There's a rabbit in our yard! Come see! What color is the rabbit? Yes, it's brown. Look, it's hopping. Now it's eating. What do rabbits eat? It looks like it's eating grass but it's probably eating clovers and other flowers. When we're done eating breakfast, let's go find some of the clovers."
Make your letter for the day "R". Use the train tracks to make railroads. Name your trains (that don't already have names) Rusty and Randy. If you're using Thomas trains, incorporate R-named trains into your story. Play blocks. Build words that start with R with the letters on the blocks. Change the word by putting a different block on top. So maybe you start with "rub". Put an “o” on the “u” and make "rob". Put a “t” on the “b” and make "rot". Let your little put blocks on and see if they make a word. Even if it doesn't make a word, try your best to say it as if it were a word. Then you can laugh at how silly the word sounds. For snack or lunch, go get some raspberries, radishes and raisins. Integrate a science lesson by asking them about their senses with the 3 foods. How does each one feel in their hands? What does each one look like? What does each one smell like? Then integrate math - ordinal numbers- by choosing which one you are going to try to eat first, second and third. Back to science, what does each one taste like? Do you like the way it tastes? What sound does it make when you eat it? Play with play dough and make the letter R in upper case and lower case. Then make things with play dough that start with R. Get out the watercolors and make a rainy picture. Read a book about R things. Walk around and see how many things you can find outside that start with R.
Et voila! You’ve integrated reading, writing, math and science into your day, inspired by nothing more extraordinary than a rabbit in your yard!