https://sites.google.com/wcpss.net/k-12mathematics/home Link to Wake County parent information.
Last week we practiced reading word problems, identifying the information that we 'know' and what do we 'want to find out'. then we used a number line to solve the equation. We also talked about the 'situation equation' (the equation that matches the word problem) can be different from the 'solution equation' (what you need to do to solve the problem.
Ex: situation equation: ____ + 38 = 66
solution equation: 66 - 38 = ____
So, we draw our number line, and put the 66 at the far right and count back by tens and ones.
We can also start at the far left with 38 and count up to 66 with tens and ones on the number line.
This helps reinforce the relationship between +/- .
We work on spacing our 'tick marks' on the number line.
We are working with turning a subtraction equation into an addition equation and counting 'up'.
ex.: 78-54= 54 + ___ = 78
start at 54 and count up using tens ( l ) and ones ( o )
54 l(64) l(74) oooo(75,76,77,78) I counted up 24. We are also learning about problem types (start unknown, change unknown and result unknown). These are word problem types. We really take the time to read a word problem and analyze what we do know and what we need to find out. Children need to be fluent with understanding whether to add or subtract. It is 1 of the 2 operations that we work with.
Practice skip counting by tens from a given number:
ex. 34-44-54-64 This will help when we work on a numberline to add/subtract larger numbers.
We are continuing to learn different addition and subtraction strategies to 99. The typical algorithm is not introduced until 4th grade. We use quick draw where a l = ten and a o = a one. This helps with 'mental strategies' instead of having to count ALL or draw 17 circles and crossing out 8 (or whatever the problem is). We work on using the language of "I started at 8 and counted up to 17 and got 9.
We also are working on +10/-10 from a given number and being able to explain that we are only changing the number in the 'tens' place because we are either adding or subtracting a 'ten'. This is an abstract concept for children at this age. Eventually we will work with +/- 100 from a 3 digit number. (remember- digits are to numbers as letters are to words).
llll ooo = 43 We group these in a 'ten frame' model.