This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place; for example, $80 - 30$ means $8 \text{ tens} - 3 \text{ tens} = 5 \text{ tens} = 50$. The specific scenario is a story where Jamal has 8 packs of 10 stickers (80) and gives away 3 packs (30). Choice B is correct because $8 \text{ tens} - 3 \text{ tens} = 5 \text{ tens} = 50$. Choice A is a common error where students miscalculate the tens subtraction, like $8 - 5$ instead of $8 - 3$; this happens because subtraction is more challenging than addition. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse ($50 + 30 = 80$); practice mental math with quick subtraction of tens; relate to real contexts like packages, dimes, groups of 10.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place. The stimulus involves counting back by tens, starting at 80 and jumping back 30 on a number line. Choice A is correct because $8 \text{ tens} - 3 \text{ tens} = 5 \text{ tens} = 50$. Choice B is a common error where students add instead of subtract, getting $80 + 30 = 110$, which happens because subtraction is more challenging than addition. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse ($50 + 30 = 80$).

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place. The stimulus involves Chen counting back by tens for 30 - 10. Choice B is correct because 3 tens - 1 ten = 2 tens = 20. Choice C is a common error where students add instead of subtract, getting 30 + 10 = 40, which happens because subtraction is more challenging than addition. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; practice mental math with quick subtraction of tens.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place; for example, 30 - 20 means 3 tens - 2 tens = 1 ten = 10. The specific scenario asks to subtract tens from tens directly in the equation 30 - 20. Choice C is correct because 3 tens - 2 tens = 1 ten = 10. Choice D is a common error where students don't convert back to the full number (say 1 instead of 10); this happens because converting from tens (1) back to the full number (10) is an extra step. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse (10 + 20 = 30); practice mental math with quick subtraction of tens; relate to real contexts like packages, dimes, groups of 10.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place; for example, 80 - 30 means 8 tens - 3 tens = 5 tens = 50. The specific scenario is Chen subtracting tens in the equation 80 - 30. Choice C is correct because 8 tens - 3 tens = 5 tens = 50. Choice A is a common error where students subtract incorrectly, like 8 - 4 instead of 8 - 3; this happens because keeping track of place value during subtraction requires practice. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse (50 + 30 = 80); practice mental math with quick subtraction of tens; relate to real contexts like packages, dimes, groups of 10.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place; for example, $70 - 60$ means $7$ tens - $6$ tens = $1$ ten = $10$. The specific scenario is Amir counting back by tens in $70 - 60$. Choice A is correct because $7$ tens - $6$ tens = $1$ ten = $10$. Choice D is a common error where students use one of the original numbers instead of finding the difference or miscalculate; this happens because keeping track of place value during subtraction requires practice. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse ($10 + 60 = 70$); practice mental math with quick subtraction of tens; relate to real contexts like packages, dimes, groups of 10.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place. The stimulus directly asks to subtract the tens for 40 - 30. Choice C is correct because $4$ tens - $3$ tens = $1$ ten = 10$. Choice A is a common error where students add instead of subtract, getting $40 + 30 = 70$, which happens because subtraction is more challenging than addition. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse ($10 + 30 = 40$).

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place; for example, 50 - 50 means 5 tens - 5 tens = 0 tens = 0. The specific scenario is subtracting equal amounts like 50 - 50. Choice B is correct because when subtracting equal amounts like 50 - 50, the result is 0. Choice A is a common error where students use one of the original numbers instead of finding the difference; this happens because students may reverse the operation. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse (0 + 50 = 50); practice mental math with quick subtraction of tens; relate to real contexts like packages, dimes, groups of 10.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place. The stimulus shows base-10 blocks representing 70-30, likely with 7 ten-rods minus 3 ten-rods. Choice B is correct because 7 tens - 3 tens = 4 tens = 40. Choice A is a common error where students add instead of subtract, getting 70 + 30 = 100, which happens because subtraction is more challenging than addition. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; connect to addition as inverse (70 - 30 = 40, check: 40 + 30 = 70); practice mental math with quick subtraction of tens; relate to real contexts like packages, dimes, groups of 10.

This question tests 1st grade subtraction of multiples of 10 in the range 10-90 (CCSS.1.NBT.6). When subtracting multiples of 10, use place value strategy: subtract tens from tens. Since both numbers end in 0 (have 0 ones), we only work with the tens place. The stimulus is a story where Jamal has 70 crayons and gives away 40. Choice A is correct because 7 tens - 4 tens = 3 tens = 30. Choice B is a common error where students add instead of subtract, getting 70 + 40 = 110, which happens because subtraction is more challenging than addition. To help students: Use base-10 blocks to physically remove ten-rods, counting what remains; practice on number lines with backward jumps of 10; emphasize 'subtract tens from tens' strategy; connect to skip counting backward by 10s; provide many examples showing pattern; use place value charts to organize tens; relate to real contexts like crayons in groups of 10.