The seven activities in this bundle were designed to address the first two standards in the Numbers in Base Ten domain at the fifth grade level. There are 3 sets of complimentary tasks and a place value chart that includes a decimal point.
Ten Times More or Less – Numbers in the 100s and 1,000s
Ten Times More or Less – Decimals
These two activities were designed to directly address CCSS Math 5.NBT.A.1 which expects students to mentally manipulate numbers using “place value” thinking by visualizing these numbers on a place value chart and then moving them either one place to the right or to the left of the original number depending on whether you are multiplying or dividing by ten. We used to teach this as moving the decimal point, but in reality, the decimal point is always located between the ones place and the tenths place. It does not move. In multiplying decimals by 10, many students overgeneralize and simply “tack on” a zero at the end, just like with whole numbers. This thinking is incorrect. These activities will help your students practice this important concept.
Multiply by 10, 100, 1,000 and 10,000
Divide by 10, 100, and 1,000
These two activities take the concept of ten times more or less and carry it a little further. These activities directly address CCSS Math 5NBT.A.2 which expects students to mentally manipulate numbers using “place value” thinking more than one place to the right or the left. Students have been taught to “tack on” a certain number of zeros when multiplying by powers of 10, but this doesn’t work with decimals so these two activities provide your students with the practice they need to visualize what is really happening to these numbers. Ask your students if they should end up with a number that is larger or smaller than the number they started with. This will help to develop this important concept.
Multiply by Powers of Ten
Divide by Powers of Ten
These two activities take this idea of moving numbers along the place value chart one step further by asking students to work with exponents as they multiply and divide powers of ten.
Place Value Chart from Hundred Billions to Thousandths
When working with the concepts described above, students need to envision what is really happening. Visualizing in math is just as important as visualizing in reading. After working with this place value chart and the activities included in this bundle, my students are able to mentally manipulate numbers using “place value” thinking rather than relying on “moving “ the decimal point because they have committed this place value chart to memory. I have included a decimal point with this chart. This seems like a minor detail, but seeing that decimal point placed in the correct position helps students understand that it has an assigned position and does not ever move. This especially helps to clear misconceptions that arise when multiplying or dividing by powers of ten.
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