We began new math learning in new math switch groups this week. Our Unit 4 in math will focus on tens and teen numbers, place value to 100, and strategies for adding larger numbers. So far, we’ve practiced counting groups of tens.
We studied the teen numbers (11, 12, 13, 14, 15, 16, 17, 18, 19) and noticed that every teen number has a 10 hiding inside along with some extra ones. We also represented teen numbers using a ten stick and circles, and wrote an equation to match our work.
Finally, we introduced our first graders to a new addition strategy called “Make a 10”. For the equation, 9 + 4 = ___, we can “count on” to find the total of 13. Since the total, 13, is a teen number (which has a 10 hiding inside) we helped our students notice that 9 + 4 = 10 + 3. Both of these equations produce the total 13, but solving 10 + 3 is quicker and more accurate.
We will spend much of our math time next week working with this new strategy as it is still very new and fragile. Please encourage your child to think about the “ten” hiding inside teen numbers when they solve equations on their homework.