That is the rule in all languages, but only for formal or literary texts.
Generally you spell out numbers that are ten or below, between eleven and twenty you can probably do as you like. The larger a number, the less likely you are to spell it out. To be safe, you can always spell out a number and add the numeral in parentheses behind. There is no particular rule for spelling out specifically when there are multiple numbers in a sentence.
a number sentence.
inequality
Insert a "less than" symbol between then: 7 < 8
The number 180000 (180,000) is spelled "one hundred and eighty thousand". (The alternate is "one hundred eighty thousand" which may be less clear without hyphenation.)
Generally you spell out numbers that are ten or below, between eleven and twenty you can probably do as you like. The larger a number, the less likely you are to spell it out. To be safe, you can always spell out a number and add the numeral in parentheses behind. There is no particular rule for spelling out specifically when there are multiple numbers in a sentence.
a number sentence.
y = 200-7
No they should get the exact same sentence as any normal person.
The letters SLASE can spell seals, or sales, or a number of shorter words such as sea(s), ale(s), as(s), and less.
A valid number sentence that is true: 3 + 7 = 10. A valid number sentence that is false: 7 + 9 = 17. A valid number sentence using a 'less than' symbol: 3 + 6 < 10.
The scramble was miscopied - there should be one less R and one more S.The letters crrrsseehea spell "researchers."
Yes, "should" is a modal helping verb in the sentence "People should drive less." It is used to express advice, recommendation, or obligation.
The terms"to, from and than" change the order of the math sentence. Four less than a number "g" is g-4.
inequality
Some style sheets suggest spelling out numbers less than 20. If there are several numbers (e.g. 4 of 14, 25 out of 99) in the sentence, they can all be written as as numbers rather than words.
If you find out that there is less money in the cash register than there should be, you have found a discrepancy.