Decimal Power: Multiplying, Dividing, and Estimating 🔢

Fifth Grade Families,

Today your fifth graders took the Unit 2 exam on decimals. We gave this unit an extra week so every student could learn to divide decimals before the test, and that extra time paid off.

What we learned. We started with multiplying decimals, shading hundredths grids to see why 0.3 x 0.4 is 0.12, then moved to the standard algorithm and counting decimal places to place the decimal point. In the last two weeks we turned to dividing decimals. Students learned to read 12 ÷ 0.2 as a question: how many groups of 0.2 fit in 12? There are 5 groups of 0.2 in every whole, so the answer is 60. Then they check it with multiplication: 60 x 0.2 = 12.

The habit that matters most. Estimate first. If you multiply 4.2 by 5.9, the answer should be close to 4 x 6, or 24. If a student gets 2.478 or 247.8, the estimate tells them the decimal point is in the wrong place.

How you can help at home. Let your child handle the receipt next time you shop. Estimating the total before checkout and comparing it to the real number is exactly the skill we built in this unit. You can also ask a division question at the store: how many 50 cent stickers can you buy with 6 dollars?

Graded exams will come home soon. Parent-teacher conferences are October 26 through 30, and I look forward to sharing how much your fifth graders have grown.

Mr. Green