What this lesson covers
This one works a question whose answer is negative, types it, and then shows the two entries that carry the same right answer and still score zero. Then the four rules that decide whether a correct value counts: five characters, six if it starts with a minus, one answer only, and no percent sign, comma or dollar sign.
00:00 Eleven questions with no choices
00:18 The format
00:42 The method
01:30 What the box accepts
01:52 Your turn
02:20 Three ways this goes wrong
02:38 Recap
Both equations are original, written for SAT Climb.
Worked examples
The questions the video works, written out: the setup, each step, the answer and the trap.
0:42Example 1
What is the value of x? There are no answer choices. The answer is typed into a box that holds up to 5 characters, or 6 if the answer starts with a minus sign.
- Distribute the 5: .
- Take 3x off both sides: .
- Take 20 off both sides: , so x = -13.
- Check: 5(-13 + 4) = 5(-9) = -45, and 3(-13) - 6 = -39 - 6 = -45. Both sides match.
- Type it: -13. That is three characters, and the minus sign is one of them. The box allows six for a negative answer, so it fits and scores.
Answer: x = -13, typed as -13
The box scores the string you typed, not the work you did. The two near misses both score zero: 13 drops the sign and is a different number, and x = -13 puts a letter and an equals sign in a box that wanted only the number. The paper SAT could not take a minus sign at all, and a student carrying that old habit turns a right answer into a wrong one.
1:52Example 2
What is the value of x? Solve it, then say exactly what you would type into the box.
- Distribute the 2: .
- Take 2x off both sides: . Take 10 off both sides: .
- Divide by 4: x = -6.
- Check: 2(-6 - 7) = 2(-13) = -26, and 6(-6) + 10 = -36 + 10 = -26. Both sides match.
- Type -6: two characters of the six allowed.
Answer: x = -6, typed as -6
Minus six is the number; 6 on its own is a different number and scores nothing. Keep the entry to the number alone: no x, no equals sign, no space. A comma inside a big number, such as 1,250 for 1250, is a symbol and also fails, and a blank costs exactly the same as a wrong entry, so always type something.
Lesson transcript
The narration of the video, word for word, under its chapter headings.
About a quarter of digital SAT math has no answer choices. Roughly eleven questions out of forty four. You solve the problem, and you type your answer into a box. Here is one. Five times the quantity x plus four, equals three x minus six. Distribute the five: five x plus twenty. Take three x off both sides, take twenty off both sides. Two x equals negative twenty six. So x is negative thirteen. Now the part students lose points on. You type negative thirteen. Three characters. The minus sign is allowed, and it counts as one of them. Drop the sign, and you have typed a different number. Type x equals negative thirteen, and the box only wanted the number. Both score zero. Four rules decide whether a right answer counts. Five characters for a positive answer. Six if it starts with a minus. If more than one value works, enter one. And no percent sign, no comma, no dollar sign. Your turn. Solve it, then say exactly what you would type. Ten seconds. Two x minus fourteen equals six x plus ten. Negative twenty four equals four x. So x is negative six. You type minus six. Three ways this goes wrong. A comma inside a big number. Leaving it blank, when a wrong entry costs exactly the same as an empty one. And typing two answers when the box wanted one. Solve it. Then type it clean.