Connecticut Grade 2 Math

A collection loses forty-six counters

A class starts with 83 counters and removes 46. How many remain? Build 83 as eight bundles of ten and three separate counters. Forty-six means four tens and six ones. The model has enough tens to remove four, but only three separate ones to remove six.

Exchange one bundle of ten for ten separate counters. Now the starting collection is seven tens and thirteen ones. It is still 83: 70 + 13 = 83. Remove six ones, leaving seven; remove four tens, leaving three. The remaining collection is three tens and seven ones, or 37.

Connect the drawing to the written method

Write 83 − 46 = 37 and annotate the model with the exchange. The tens count changes from eight to seven because one ten was unpacked. The ones count changes from three to thirteen because ten ones were added to that part of the representation. Nothing was added to the total collection.

Ask why 83 can be written as 70 + 13. A child who says “borrow a one” may need to name the value of that one: it is one ten, equivalent to ten ones. Moving a mark on paper without identifying the unit can make the procedure look arbitrary.

Investigate a common wrong answer

An answer of 43 can result from subtracting the smaller digit from the larger in each column: 8 − 4 and 6 − 3. But the story removes 46 from 83, not three ones from six. Return to the starting collection and ask which counters are actually being removed. Reversing only the ones calculation changes the problem.

Check the result through addition: 37 + 46 = 83. Seven ones and six ones combine into thirteen ones; regroup ten of them into one ten. Three tens, four tens, and that extra ten make eight tens, with three ones left. The addition check uses the same unit exchange in the opposite direction.

Test the explanation in a new case

Try 92 − 58. Represent 92 as eight tens and twelve ones, then remove five tens and eight ones to obtain 34. Ask the student to show why that representation still equals 92 and verify 34 + 58 = 92. If the unit exchange is clear but arithmetic facts are slow, practice those facts separately. If the exchange is unclear, keep the model and ask for a spoken explanation before assigning more written calculations.

Selected Connecticut Grade 2 references

The Connecticut mathematics standards directory links the Core Standards publisher. The state’s Core Standards overview identifies adoption in 2010 and explains that districts develop local curricula. These labels summarize the activity’s focus; read the complete expectations and mathematical practices in the publisher’s mathematics document.

Sources checked October 5, 2026. This selected activity is an entry point for instruction, not a complete curriculum checklist.

Connect the explanation with practice

Visit the Grade 2 math learning Online Center for broader support or browse available practice through the worksheet finder. This is a general collection, not a certification of complete Connecticut alignment.

Grade 2 is below Connecticut’s Smarter Balanced mathematics testing range, which begins in Grade 3. Use classroom observations, models, and explanations to plan early learning. Read Connecticut’s official summative assessment overview.

Keep one example of the student’s reasoning with the practice result. Choose a smaller model, a related question, or a new context according to the difficulty revealed in the worked activity.

Connecticut Grade 2 math: useful study questions