Over the next few weeks we will be revising, exploring and extending our thinking around efficient & different strategies to solve problems involving SUBTRACTION. Having automatic recall of facts under twenty will be very helpful in this work. It would be great for your child to be practising their recall of subtraction facts.
We will also be ensuring that we understand how to apply strategies we used to solve addition to subtraction – we will need to carefully rethink a few of these. A favourite will be using empty or open number lines to use the jump strategy. This is a great way to demonstrate how to think flexibly about numbers. It is also a great way to encourage mental calculations.
As we finished Term One we were consolidating and extending our understanding of a variety of strategies to solve addition equations. We reviewed the use of the jump strategy and the split strategy. These strategies involve us using lots of different thinking. By the end of Year Four it is expected that students can : apply place value to partition, rearrange and regroup numbers to at least tens of thousands to assist in calculations and solve problems
The jump strategy uses an empty (or open) number line. To use this strategy students must break one of the addends into parts to make it easier to add. This strategy really encourages students to think flexibly about numbers and is a stepping stone to mental calculations.
The Split Strategy also requires students to think about place value. One or both of the addends needs to be decomposed into useful parts to make them easier to add to each other. It can look like these examples…
Our focus has been on exploring strategies that allow for students to come to a solution in a way that makes sense to them – with many steps or fewer steps. There is no one way to get to the answer.
Being able to add tens or hundreds onto a number is a really important skill for both of these strategies to work. You might like to practise doing this quickly. For example: 23 + 10, 56 + 30, 67 + 20, 123 + 100, 345 + 200, etc.
Here a few fact sheets that explain these two strategies to mums & dads:
The Victorian Curriculum states that Year Four students need to be able to model, represent and order numbers to tens of thousands. For the last two weeks this has been the focus of our Maths lessons.
We have had some great sessions using interactives to help consolidate and extend our understanding of place value. We have focused on understanding that each digit in a number holds a place and has value:
We have also been practicing writing numbers in three forms:
Some students are finding it tricky to remember that at times zero has a very important job at holding a place despite having no value.(Zero as a place holder-1b3ql7d). This is especially important as we read and write numbers that have 5 digits and more such 80 123 or 45 604. It would be good to practice reading, writing and expanding these numbers at home.
A fun thing we did in class was watch a YouTube clip like this one:
Then randomly I would press pause and the number that was on the screen, students had to read and record the expanded notation for. Have ago at home…
You might also like to use some of these websites for further practice (especially if you are having trouble with Studyladder)
We have commenced our investigation into MEASUREMENT with the Potato Olympics. Each coach created a Spudlete, which competed in three events. Each event helped us to discover that when you measure you need to use a specific tool and each measurement has a name. We measured weight in grams, on scales. We measured distance (length) in centimetres, using a measuring tape. We measured time in seconds, using a stopwatch. We also had a lot of fun exploring and some laughs together…
Can you practice doing some measuring at home? Have you got some kitchen scales? Have you got a watch? What other measuring tools can you find around your house?
We have discovered that there are many ways to show a multiplication fact: equal groups of, repeated addition, an array, and a number sentence (which has a turn around fact).
Here are some examples so mums & dads know what the different ways look like…
Remember the first number in the fact represents how many groups (or how many times we have to add, or how many rows there will be) and the second number is what we are counting by (or adding repeatedly or will be in each group or in each row). Good luck!
If Gold=3 points, Silver=2 points, Bronze =1 point…
How many points do the top 5 teams have?
Explain how you worked it out.
Our Inquiry unit this term has been called “Dare to fail and to succeed.” I wonder if this applies to the athletes participating in the Olympic games? What can we learn from the athletes about having a growth mindset?
Before we learn to recall time table facts, it is important that we understand that multiplication is about:
We also have just discovered that multiplication has a commutativity property just like addition. For example 2 groups of 10 is 20 and 10 groups of 2 is also 20. The total is the same but what we count by & how many times we count changes.
Can you practice making some groups of (lots of, fish tanks of, baskets of, vases of) at home?